Rita Salisbury, More on the Mission, April 23, 2013

CDTs record conductivity, depth,  and temperature

CDTs record conductivity, depth, and temperature

NOAA Teacher at Sea
Rita Salisbury

Aboard NOAA ship Oscar Elton Sette
April 14-April 29, 2013

Mission: Hawaii Bottomfish Survey
Geographical Area of Cruise: Hawaiian Islands
Date:
Tuesday, April 23, 2013

Science and Technology Log

CDT being lowered over the starboard side

CDT being lowered over the starboard side

A few days ago we dropped the CDT, an apparatus that collects data on the conductivity, the depth, and the temperature of the sea water in which the acoustic survey is taking place. All of these three things impact how quickly sound travels underwater. The scientists collect the information and then use it to figure out an accurate rate of speed for the sound waves. Once they have that information, they can determine how far a target is from the ship.I was able to ride along in a small boat to Maui to pick up parts for the AUV. While in the Maui harbor, I had the opportunity to visit the Huki Pono, a small boat working on this survey that is using BotCams to survey the fish population. The palu, or bait, that I help make every day is frozen and then transferred to the fishing boats. It is frozen in a shape that fits into a cage on the BotCam located near the camera. As the bait breaks up, fish are attracted to it and come close enough to the BotCam to be visually recorded. There is a lot of video to go through so Dr. Kobayashi says they won’t have the data from the BotCams for a while.  But the other three fishing boats assigned to this project turn their survey information in every evening and I get to add it to a spreadsheet to help keep track of what section the boats were in and what they found while they were there.

BotCam on the deck of the Huki Pono

BotCam on the deck of the Huki Pono

Chris Demarke, Jamie Barlow, and Bo Alexander retrieving a BotCam aboard the Huki Pono with Maui in the background
Work continues with the ROV and AUV. The scientists are always working on them, trying to make them run as smoothly as possible. We worked on calibrating the acoustics again this morning for the same reason. The better the information you have when you start a project, the better chance you have of having a successful outcome.

As I mentioned before though, not everything we are doing is high tech. We fish off the side of the ship in the evenings, dropping our lines all the way to the bottom so they are on the sea floor. The scientists running the acoustics tell us if they see fish and then we do our best to catch a representative sample.  Here are two of the fish I caught off the bottom: an opakapaka and a taape. The observers that ride in the small boats every day spend the night on the Sette. That way, they can turn their logs in and I can record the data. As a bonus, a few of them are expert fishermen and are a huge help to us as we fish from the ship.

Opakapaka and ta'ape

Opakapaka and ta’ape

Personal Log
I’m really enjoying my time on the Sette. In addition to learning new things that I can apply in my classroom, I’m making new friends. Everyone is exceptionally friendly and they go out of their way to explain things to me. Most of them call me “Teach” or “Taz” and almost all of them have sailed with a Teacher at Sea before.

Did You Know?
You can tell the age of a fish by their otoliths? The picture has the otoliths from an opakapaka, an ehu, and a hogo. Otoliths are a fish’s “ear bones” and they have growth lines in them much like a tree has growth rings.

Otoliths

Otoliths

Additional Section

Why are these bottom-dwelling fish red?

Red fish?

Red fish?

Rita Salisbury: Robots and Sound Waves, April 19, 2013

NOAA Teacher at Sea
Rita Salisbury
Aboard NOAA ship Oscar Elton Sette
April 14-29,  2013

 

Mission: Hawaii Bottomfish Survey
Geographical Area of Cruise: Hawaiian Islands
Date: April 19 2013

 

Weather Data from the Bridge
Partly cloudy, winds ENE 10-15 knots, sunrise 603, sunset 1846
77 degrees F (25 degrees C)
Humidity 85%
Barometer 30.09” (1019.5 mb)
Dewpoint 72 degrees F (22 degrees C)
Heat Indes 78 degrees F (26 degrees C)
Visibility 10 miles

Science and Technology Log

We have been calibrating the acoustic equipment for a few days in order to be ready for our survey of bottomfish. It was a long process, but necessary. Four of us worked on moving a small titanium sphere under the boat by maneuvering it to different positions. A scientist working in the e-lab (electronics lab) used different frequencies from the transducers to locate the sphere and record the results. Graduate students and NOAA scientists worked until 1:00 in the morning to get the job done.

The ROV on it's first deployment

The ROV on it’s first deployment

While we were working on the acoustics, other scientists were working on a test run of the ROV. The currents were very strong when they deployed the ROV but it performed well and was successfully retrieved. Operating it is a lot like the controls to a video game, only the stakes are much higher. 

The AUV was deployed on Wednesday. The first step was to do a rehearsal of the procedures for deploying and retrieving the AUV. Everyone had a job to do and it was made clear who would be doing what and when. While it was obvious that certain people were in charge, they asked that if anyone thought they had a better idea of how to do something, or had a question, to speak up.  At one point, the captain, CO Koes, asked everyone who was not actually part of the procedure to move to one of the side of the deck so she could see who was  actually supposed to be working.

After the walk-through rehearsal, the AUV was lifted off the deck by a large crane and placed into the water off the fantail of the ship. At first it was tethered to the ship, but after awhile it was released and became independent of the ship. The scientists want to be as sure as they can be that the AUV will operate properly before letting it go so they run through a checklist. If everything is working correctly, they release the AUV.

OLYMPUS DIGITAL CAMERA

The AUV being deployed.

OLYMPUS DIGITAL CAMERA

The AUV going solo!

The AUV is pre-programmed for the mission so it is important to know about the underwater geography of an area. The AUV needs to be within 30 to 35 meters of the ocean floor in order to know where it is. Other than that, it follows the pattern that the scientists created. If the AUV doesn’t return to the ship, it’s a big deal. It’s very expensive and difficult to replace. The scientists designed it with that thought in mind.

In addition to the high-tech solutions programmed into the AUV, the scientists also included low-tech ideas into the equipment to retrieve the AUV in case something goes wrong and the AUV is submerged and unretrievable. There is a “drop weight” attached to a strand of zinc. Zinc corrodes quickly in salt water. Through testing the scientists have already determined how thick the zinc strand should be in order to corrode through in a given amount of time at a particular water temperature. The strand that they are using on this cruise is constructed to corrode through in 5 1/2 hours. Once it corrodes, the weight drops off and the AUV rises to the top of the water where it can be seen and picked up. The zinc strand is replaced and another weight is attached. All the weights are the same size and weight so they are interchangeable. Otherwise, the scientists would have to recalibrate the AUV every time they changed weights. I was really impressed to see that the scientists use a combination of high and low tech to make their AUV successful.

Heat-sealing the ground up squid and sardines for bait.

Heat-sealing the ground up squid and sardines for bait.

The scientists on the Oscar Elton Sette use some smaller boats to assist with their research. One thing that I do to help out is make bait for the small boats to use to attract fish. We take frozen squid and sardines out of the freezer a few hours before we need them and put them on a protected place on the deck. After they thaw, we put them in a commercial quality food processor and grind them up into marble-sized chunk. Then we put the chunky bait into plastic bags, seal them, and put them back in the freezer until they can be delivered to the boats that need them.

Personal Log

This ship is amazing! It’s big and packed with the scientific equipment. The “wet lab” has become the acoustics lab for this trip and the e-lab is above that. The mess is open 24 hours for snacks, (as long as you clean up after yourself), and serves three meals a day. The cooks are really talented and are always providing fresh new ways of serving something. Fortunately, there’s a gym a couple of decks beneath mine!

There’s a movie room, a laundry, a tv room with books and computers, and a ship’s store. There’s even a full-time medical officer on board. My stateroom is set up well. There are 6 spacious bunks, drawers under the bottom ones and lockers for everyone, built-in desks with ethernet access, and a large bathroom. Since everyone is on a slightly different schedule we do our best to be quiet and to keep the lights low.

Uli Uli Manu taking a break on my bunk.

Uli Uli Manu taking a break on my bunk.

 On Tuesday, we had emergency drills. Everyone has a specific place that have to go to when the alarms sound. If it’s a fire alarm or a man-overboard drill, I have to go to the Texas Deck. If it’s an abandon ship drill, I go to the boat deck and put on my orange gumby suit. That was a little tricky and very hot, but I’m glad they let us practice it.

One thing I’ve noticed on the ship is how everyone has a job to do, but they are always ready to pitch in and help someone else. Meals are really interesting. The mess is small and has several tables set up with 4 chairs at each table. People sit with different people all the time. It doesn’t seem to matter who is an officer, a crew member, or a scientist. Everyone sits with everyone else.

 The captain gave me a tour of the bridge on Tuesday. It was late and we ran out of time, so she has invited me to come back up and finish the tour

The Oscar Elton Sette as seen from a small boat off the coast of Maui.

The Oscar Elton Sette as seen from a small boat off the coast of Maui.

soon. I was impressed by the number of back-up plans in place. There didn’t seem to be one piece of equipment that didn’t have another piece doing the same job in a slightly different way. This allows the ship to continue working properly on the chance that something stops working. The bridge is the control center of the ship and has alarms and notifications for anything that might crop up–low fresh water levels, smoke, fire, and anything else you can think of.

Did You Know?

Sound is vibration transmitted through a solid, liquid, or gas. The speed of the vibrations, or how quickly they cycle, determines the frequency. Frequency is measured in cycles per second, or hertz (Hz). Humans can hear certain frequencies, while bats and dogs can hear others. Whales and dolphins hear even more frequencies.

The sound waves we are using on the Oscar Elton Sette will bounce off the fish and reflect back to the ship, allowing the scientists to locate the fish and determine their shape, size, and movement.

 

Animals I Have Seen

Whale fluke off Maui

Whale fluke off Maui

Seen off the coasts of Maui, Molokai, and Lanai:

Needlefish
I thought they were barracuda at first, but someone explained the difference to me
Humpback Whales
Dolphins–too far away to identify the species

Allan Phipps: Looking Ahead: The Future of NOAA Fish Surveys? August 10, 2012

NOAA Teacher at Sea
Allan Phipps
Aboard NOAA Ship Oscar Dyson
July 23 – August 11, 2012

The Oscar Dyson at anchor in Captains Bay during calibration procedures.

Mission: Alaskan Pollock Mid-water Acoustic Survey
Geographical Area: Bering Sea
Date: August 10, 2012
.

Location Data
Latitude: 53°54’41″ N
Longitude: 166°30’61″ E
Ship speed:  0 knots (0 mph) In Captains Bay at Dutch Harbor during calibration.

Weather Data from the Bridge
Wind Speed:  17 knots (19.5 mph)
Wind Direction: 184°
Wave Height:   1-2 ft
Surface Water Temperature: 10.2°C (50.4°F)
Air Temperature: 12.5°C (54.5°F)
Barometric Pressure:   1005.9 millibars (0.99 atm)

Science and Technology Log:

Imagine a time when fish surveys could be done through remote sensing, thus eliminating the need to catch fish via trawling to verify fish school composition, length, weight, and age data.  During our “Leg 3” of the Alaska Pollock Acoustic Midwater Trawl Survey, we caught, sorted, sexed, and measured 25 tons of pollock!  While this amounts to only 0.002% of the entire pollock quota and 0.00025% of the pollock population, wouldn’t it be nice if we could determine the pollock population without killing as many fish?

Cam-Trawl sitting on deck after several successful trawls.

Introducing the “Cam-Trawl,” a camera-in-net technology that NOAA scientists Kresimir and Rick are developing to eventually reduce, if not eliminate, the need to collect biological specimens to verify acoustic data.  Cam-Trawl consists of a pair of calibrated cameras slightly offset so the result is a stereo-camera.

The importance of setting up a stereo-camera is so you can use the slightly different pictures taken at the same time from each camera to calculate length of the fish in the pictures.  Eventually, a computer system might use complex algorithms to count and measure length of the fish that pass by the camera.  If the kinks are worked out, the trawl net would be deployed with the codend open, allowing fish to enter the net and flow past the camera to have their picture taken before swimming out of the open end of the net.  Some trawls would still require keeping the codend closed to determine gender ratios and weights for extrapolation calculations; however, the use of Cam-Trawl would significantly reduce the amount of pollock that see the fish lab of the Oscar Dyson.  On this leg of the survey, the NOAA scientists installed the Cam-Trawl in a couple of different locations along the trawl net to determine where it might work best.

Installing Cam-Trawl into the side of the AWT trawl net so the NOAA scientists may capture image data during trawls.

Below are some photos taken by Cam-Trawl of fish inside the AWT trawl net.  Remember, there are two cameras installed as a stereo-camera that create two images that are taken at slightly different angles.  In the photos below, I only picked one of the two images to show.  In the video that follows, you can see how scientists use BOTH photos to calculate the lengths of the fish captured on camera.

Pollock (Theregra chalcogramma) as seen by Cam-Trawl.

A Sea Nettle (Chrysaora melanaster)  jellyfish at top right, Chum Salmon (Oncorhynchus keta ) at bottom right, and Pacific Herring (Clupea harengus) on the left as seen by Cam-Trawl installed in the AWT trawl net.

Another NOAA innovation using stereo cameras is called “Trigger-Cam.” Trigger-Cam is installed into a crab pot to allow it to sit on the ocean floor.  For this type of camera deployment, the NOAA scientists removed the crab pot net so they would not catch anything except pictures.

Trigger-Cam back on the deck of the Oscar Dyson after a successful test run.

The real innovation in the Trigger-Cam is the ability to only take pictures when fish are present.  Deep-water fish, in general, do not see red light.  The Trigger-Cam leverages this by using a red LED to check for the presence of fish.  If the fish come close enough, white LEDs are used as the flash to capture the image by the cameras.

Skilled Fisherman Jim lowering down the “heart” of Trigger-Cam for a trial run. On this dip, Trigger-Cam went down to 100 meters. Several of these tests were done before installing Trigger-Cam into a crab pot.

The beauty of this system is that it uses existing fishing gear that crab fishermen are familiar with, so it will be easily deployable.  Another stroke of brilliance is that the entire device will cost less than $3,000.   This includes the two cameras, lights, onboard computer, nickel-metal hydride batteries, and a pressure housing capable of withstanding pressures of up to 50 atmospheres (500 meters) as tested on the Oscar Dyson!  Here is a short animated PowerPoint that explains how Trigger-Cam works.  Enjoy!

Here are a couple of picture captured by the Trigger-Cam during trials!

Two pictures taken from Trigger-Cam during testing.

While these pictures were captured during tests in Dutch Harbor, they do provide proof-of-concept in this design.  With a cheap, easily deployable and retrievable stereo-camera system that utilized fishing gear familiar to most deck hands, Trigger-Cams might contribute to NOAA’s future technology to passively survey fish populations.

NOAA scientists Kresimir Williams (in center), Rick Towler (on right), and me, after assembling and testing another stereo-camera system for a NOAA scientist working on the next cruise. Kresimir and Rick designed and built Trigger-Cam!

Personal Log:

A little fun at sea!  We needed to do one last CTD (Conductivity, Temperature, Depth), and decided to lower the CTD over deep water down to 500 meters (1,640.42 ft)!  Pressures increases 1 atmosphere for every 10 meters in depth. At 500 meters, the pressure is at 50 atmospheres!!!  We wondered what would happen if… we took styrofoam cups down to that depth.  We all decorated our cups and put them in a net mesh bag before they took the plunge.  Here is a picture showing what 50 atmospheres of pressure will do to a styrofoam cup!

Three styrofoam cups that went 500 meters deep in the Bering Sea! These cups were originally the size of the undecorated white styrofoam cup in the background.

We missed the Summer Olympics while out on the Bering Sea.  T-T  We did get in the Olympic spirit and had a race or two.  Here is a little video in the spirit of the Olympics…

All for now… We are back in Captains Bay, Dutch Harbor, but are calibrating the hydroacoustic equipment at anchor.  Calibration involves suspending a solid copper sphere below the ship while the NOAA scientists check and fine-tune the different transducers.  This process will take about 7 hours!  We have been out at sea for 3 weeks, are currently surrounded by land, but must wait patiently to finish this last and very important scientific task.  If the calibration is off, it could skew the data and result in an inaccurate population estimation and quotas that may not be sustainable!  This Landlubber can’t wait to have his feet back on terra firma.  The thought of swimming crossed my mind, but I think I’ll wait.  Then we will see if I get Land Sickness from being out at sea for so long…

Allan Phipps: Shhh! Be very, very quiet! We’re hunting pollock! August 7, 2012

NOAA Teacher at Sea
Allan Phipps
Aboard NOAA Ship Oscar Dyson
July 23 – August 11, 2012

Fun with Blue King Crab (Paralithodes platypus)!

Mission: Alaskan Pollock Midwater Acoustic Trawl Survey
Geographical Area: Bering Sea
Date: August 7, 2012

Location Data
Latitude: 60°25’90″ N
Longitude: 177°28’76″ W
Ship speed:  3 knots (3.45 mph)

Weather Data from the Bridge
Wind Speed:  5 knots (5.75 mph)
Wind Direction: 45°
Wave Height:   2-4 ft with a  2 ft swell
Surface Water Temperature: 8.6°C (47.5 °F)
Air Temperature: 8°C (46.4 °F)
Barometric Pressure: 1019 millibars (1 atm)

Science and Technology  Log:

In my last blog, we learned about how the scientists onboard the Oscar Dyson use some very sophisticated echo-location SONAR equipment to survey the Walleye pollock population.

Can the Walleye pollock hear the “pings” from the SONAR?

No.  Unlike in the movies like “The Hunt for Red October” where submarines are using sound within the human audible range to “ping” their targets, the SONAR onboard the Oscar Dyson operates at frequencies higher than both the human and fish range of hearing.  The frequency used for most data collection is 38 kHz.  Human hearing ranges from 20 Hz to 20 kHz.  Walleye pollock can hear up to 900 Hz.  So, the pollock cannot hear the SONAR used to locate them…

Can the Walleye pollock hear the ship coming?

Normally, YES!  Fish easily hear the low frequency noises emitted from ships.

A comparison of hearing ranges for various organisms showing the anthropogenic source noise overlap (courtesy of oceannavigator.com).

If you are operating a research vessel trying to get an accurate estimate on how many fish are in a population, and those fish are avoiding you because they hear you coming, you will end up with artificially low populations estimates!  The International Council for the Exploration of the Seas (ICES) established noise limits for research vessels that must be met in order to monitor fish populations without affecting their behavior.  Fish normally react to a threat by diving, and that reduces their reflectivity or target strength, which reduces the total amount of backscatter and results in lower population estimates (see my last blog).

A comparison of two ships and fish reaction to the noise produced by each.  The Oscar Dyson has a diesel electric propulsion system as one of its noise reduction strategies.  Notice the smaller noise signature (in blue) and fewer fish avoiding (diving) when the ship approaches (www.uib.no).

That is why NOAA has invested in noise-reducing technology for their fish survey fleet.  The Oscar Dyson was the first of five ships build with noise-reducing technology.  These high-tech ships have numerous strategies for reducing noise in the range that fish might hear.

There are two main sources of engine noise onboard a ship:  machinery noise and propeller noise.

The two main sources of ship noise. (www.nmfs.noaa.gov/pr/pdfs/acoustics/session2_fischer.pdf)

The best acoustic ship designs are going to address the following:

1)   Address hydrodynamics with unique hull and propeller design.

2)   Use inherently quiet equipment and choose rotating rather than reciprocating equipment.

3)   Use dynamically stiff foundations for all equipment (vibration isolation).

4)   Place noisier equipment toward the centerline of the ship.

5)   Use double-hulls or place tanks (ballast and fuel tanks) outboard of the engine room to help isolate engine noise.

6)   Use diesel electric motors (diesel motors operate as generators while electric motors run the driveshaft.

Propeller Design:

The U.S. Navy designed the Oscar Dyson’s hull and propeller for noise quieting.  This propeller is designed to eliminate cavitation at or above the 11 knot survey speed.  Not only does cavitation create noise, it can damage the propeller blades.

Photo of cavitation caused by a propeller. These air bubbles that form along the edge of the blades can cause damage to the propeller and cause excess noise. (www.thehulltruth.com/boating-forum/173520-prop-cavitation-burn-marks.html)

Hull Design:

The Oscar Dyson’s hull has three distinguishing characteristics which increase its hydrodynamics and reduce noise by eliminating bubble sweep-down along the hull.  The Oscar Dyson has no bulbous bow, has a raked keel line that descends bow to stern, and has streamlined hydrodynamic flow to the propeller.

An artist rendition of the NOAA FRV-40 Class ships. Notice the unique hull design. (http://www.noaanews.noaa.gov/stories2004/images/bigelow2.jpg)

Vibration Isolation:

To reduce a ship’s noise in the water, it is absolutely crucial to control vibration.  The Oscar Dyson has four Caterpillar diesel gensets installed on double-stage vibration isolation systems.  In fact, any reciprocating equipment onboard the Oscar Dyson is installed on a double-stage vibration isolation system using elastomeric marine-grade mounts.

A picture of one of the Caterpillar diesel generators before installation in the Oscar Dyson. Notice the double vibration isolation sleds to reduce noise (www.nmfs.noaa.gov/pr/pdfs/acoustics/session2_fischer.pdf).

Since the diesel engines are mounted on vibration isolation stages, it is necessary to also incorporate flexible couplings for all pipes and hoses connecting to these engines.

A look at one of the four diesel generators onboard the Oscar Dyson. Notice the black flexible hose couplings in place to allow vibration isolation in the white pipes.

Any equipment with rotating parts is isolated with a single-stage vibration system.  This includes equipment like the HVAC, the electric generators for the hydraulic pumps, and the fuel centrifuges that remove any water and/or particles from the fuel before the fuel is pumped to the diesel generators.

A close-up of the single sled vibration isolation system supporting the hydraulic pumps that run the deck winches.

 

Low Noise Equipment:

The only equipment that does not use vibration isolation stages are the two Italian-made ASIRobicon electric motors that are mounted in line with the prop shaft.  Both are hard-mounted directly to the ship because they are inherently low-noise motors.  This is one of the benefits of using a diesel-electric hybrid system.  The diesel motors can be isolated in the center of the ship, near the centerline and away from the stern.  The electric motors can be located wherever they are needed since they are low noise.

Even the propeller shaft bearings are special water-lubricated bearings chosen because they have a low coefficient of friction and superior hydrodynamic performance at lower shaft speeds resulting in very quiet operation.  They use water as a lubricant instead of oil so there is a zero risk of any oil pollution from the stern tube.

Acoustic Insulation and Damping Tiles:

The Oscar Dyson uses an acoustic insulation on the perimeter of the engine room and other noisy spaces.  This insulation has a base material of either fiberglass or mineral wool.  The middle layer is made of a high transmission loss material of limp mass such as leaded vinyl.

The Oscar Dyson also has 16 tons of damping tiles applied to the hull and bulkheads to reduce noise.

The Results:

All of these noise-reducing efforts results in a fully ICES compliant research vessel able to survey fish and marine mammal populations with minimal disturbance.  This will help set new baselines for population estimates nationally and internationally.

A comparison of the Oscar Dyson and the Miller Freeman. Notice that the Oscar Dyson is at or below the standards set by ICES (http://icesjms.oxfordjournals.org/content/65/4/623.full).

As you can see from the graph above, The Oscar Dyson is much quieter than the Miller Freeman, the ship that it is replacing.  You can see the differences in the hull design from the picture below.

The quieter Oscar Dyson (on right) replaced the noisy Miller Freeman (on left) http://www.afsc.noaa.gov.

Next blog, I will write about new, cutting edge technology that might reduce the need for biological trawling to verify species.

Sources:

Special thanks to Chief Marine Engineer Brent Jones for the tour of the engineering deck and engine room, and for the conversations explaining some of the technology that keeps the Oscar Dyson going.

http://marine.cat.com/cda/files/1056683/7/VRS_Commercial+Vessel+3512B%26+Commercial+Vessel+3508B+Workboat+(6-2005).pdf

www.maritimejournal.com/features101/power-and-propulsion/no_noise_for_noaa

www.publicaffairs.noaa.gov/nr/pdf/aug2002.pdf

www.nmfs.noaa.gov/pr/pdfs/acoustics/session2_fischer.pdf

http://icesjms.oxfordjournals.org/content/65/4/623.full

Personal Log:

I found out drills aboard ships are serious business!  Unlike a fire drill at school where students meander across the street and wait for an “all clear” bell to send them meandering back to class, fire drills on a ship are carefully executed scenarios where all crew members perform very specific tasks.  When out at sea, you cannot call the fire department to rescue you and put out a fire.  The crew must be self-reliant and trained to address any emergency that arises.  When we had a fire drill, I received permission from Commanding Officer Boland to leave my post (after I checked in) and watch as the crew moved through the ship to locate and isolate the fire.  They even used a canister of simulated smoke to reduce visibility in the halls similar to what would be experienced in a real fire!

Robert and Libby suit up during a fire drill!

Late last night, we finished running our transects!  Our last trawl on transect was a bottom trawl which brought up some crazy creatures!  Here are a couple of photos of some of the critters we found.

From left to right, Blue King Crab (Paralithodes platypus), Alaska Plaice (Pleuronectes quadrituberculatus), Red Irish Lord eating herring on the sorting table (Hemilepidotus hemilepidotus), and Skate (unidentified).

Next blog will probably be my last from Alaska.  T-T

Johanna Mendillo: Hello pollock…. can you hear me now? August 7, 2012

NOAA Teacher at Sea
Johanna Mendillo
Aboard NOAA ship Oscar Dyson
 July 23 – August 10

Mission: Pollock research cruise
Geographical area of the cruise: Bering Sea
Date: Tuesday, August 7, 2012

Location Data from the Bridge:
Latitude: 59 52 ’ N
Longitude: 177 17’ W
Ship speed:   8.0 knots ( 9.2 mph)

Weather Data from the Bridge:
Air temperature: 7.3C (45.1ºF)
Surface water temperature: 8.4C (47.1ºF)
Wind speed:  4 knots ( 4.6 mph)
Wind direction: 75T
Barometric pressure:  1018 millibar (1 atm)

Science and Technology Log:

We are wrapping up our final few sampling transects.  Now that you are practically fisheries biologists yourselves from reading this blog, students, we must return to the fundamental question— how do we FIND the pollock out here in the vast Bering Sea?  The answer, in one word, is through ACOUSTICS!

Look at all of these birds off the stern!  Why do you think they are following us?  Are we about to haul up a catch, perhaps?

Look at all of these birds off the stern! Why do you think they are following us? Are we about to haul up a catch, perhaps?

Hydroacoustics is the study of and application of sound in water.  Scientists on the Oscar Dyson use hydroacoustics to detect, assess, and monitor pollock populations in the Bering Sea.

Now, you may have heard of SONAR before and wonder how it connects to the field of hydroacoustics.  Well, SONAR (SOund Navigation and Ranging) is an acoustic technique in which scientists send out sound waves and measure the “echo characteristics” of targets in the water when the sound waves bounce back— in this case, the targets are, of course, the pollock!  It was originally developed in WWI to help locate enemy submarines!  It has been used for scientific research for over 60 years.

(PLEASE NOTE: The words sonar, fishfinders, and echosounders can all be used interchangeably.)

The transducer sends out a signal and waits for the return echo...

The transducer sends out a signal and waits for the return echo once it bounces off the fish’s swim bladder… (Source: http://www.dosits.org)

On the Dyson, there is, not one, but a collection of five transducers on our echosounder, and they are set at five different frequencies.  It is lowered beneath the ship’s hull on a retractable centerboard.  The transducers are the actual part of the echosounder that act like antennae, both transmitting and receiving return signals.

The transducers transmit (send out) a “pulse” down through the water, at five different speeds ranging from 18-200kHz, which equals 18,000-200,000 sound waves a second!

When the pulse strikes the swim bladders inside the pollock, it gets reflected (bounced back) to the transducer and translated into an image.

First of all, what is a swim bladder?  It is simply an organ in fish that helps them stay buoyant, and, in some cases, is important for their hearing.

Swim Bladder (Source: www.education.com)

Swim Bladder (Source: http://www.education.com)

Now, why do the pulses bounce off the swim bladders, you ask?  Well, they are filled mostly with air and thus act as a great medium for the sound waves to register and bounce back.

Think of it this way: water and air are two very different types of materials, and they have very different densities.  The speed of sound always depends on the material through which the sound waves are traveling through.  Because water and air have very different densities, there is a significant difference in the speed of sound through each material, and that difference in speed is what is easy for the sonar to pick up as a signal!

It is the same idea when sound waves are used to hit the bottom of the ocean to measure its depth- it is easy to read that signal because the change in material, from water to solid ground, produces a large change in the speed of the sound waves!

Here is a sonar system measuring the depth of the ocean...

Here is a sonar system measuring the depth of the ocean… (Source: http://www.dosits.org)

Interestingly, different types of fish have different shaped and sized swim bladders, and scientists have learned that they give off different return echos from sonar signals!  These show up as slightly different shapes on the computer screen, and are called a fish’s “echo signature”.  We know, however, that we will not encounter many fish other than pollock in this area of the Bering Sea, so we do not spend significant time studying the echo signatures on this cruise.

So, what happens when these signals return to the Dyson?  They are then processed and transmitted onto the computer screens in the hydroacoutsics lab on board.  This place is affectionately known as “the cave” because it has no windows, and it is, in fact, the place where I spend the majority of my time when I am not processing fish!  Here it is:

Here is Anatoli observing potential fish for us to go catch!

Here is Anatoli observing potential fish for us to go catch!

We spend a lot of time monitoring those computer screens, and when we see lots of “specks” on the screen, we know we have encountered large numbers of pollock!

Here we are approaching a LARGE group of pollock!

Here we are approaching a LARGE group of pollock!

When the scientists have discussed and confirmed the presence of pollock, they then call up to the Bridge and announce we are “ready to go fishing” at a certain location and a certain depth range!  Then, the scientists will head upstairs to the Bridge to work with the officers and deck crew to supervise the release, trawling, and retrieval of the net.

Now, in addition to the SONAR under the ship, there are sensors attached to the top of the net itself, transmitting back data.  All of the return echos get transmitted to different screens on the bridge, so not only can you watch the fish in the water before they are caught, you can also “see” them on a different screen when they are in the net!  As I told you in the last post, we will trawl for anywhere from 5-60 minutes, depending on how many fish are in the area!

Left: Echosounder at work/  Right: The "return signature" is visible on the computer!

Left: Echosounder at work/ Right: The “return signature” is visible on the computer!  (Source: http://www.dosits.org)

A full catch- success!  Without acoustics, it would be much harder for NOAA to monitor and study fish populations.

A full catch- success! Without acoustics, it would be much harder for NOAA to monitor and study fish populations.

Personal Log:

In these last few days, we have crossed back and forth from the Russian Exclusive Economic Zone (EEZ) and the U.S. several times.  There were some nice views of Eastern Russia before the clouds and fog rolled in!

I can see Russia from my ship!

I can see Russia from my ship! (Photo Credit: Allan Phipps)

In addition, we crossed over the International Date Line!  It turns out that everyone on board gets a special certificate called the “Domain of the Golden Dragon” to mark this event.  This is just one of a set of unofficial certificates that began with the U.S. Navy!  If you spend enough time at sea, you can amass quite a collection- there are also certificates for crossing the Equator, Antarctic Circle, Arctic Circle, transiting the Panama Canal, going around the world, and more…

I will award a prize to the first person who writes back to tell me what does it mean when one goes from a “pollywog” to a “shellback”, in Navy-speak!

Here is a picture of me with the largest pollock I have seen so far- 70cm!

If I am 5' 4", how many 70cm pollock would it take to equal my height?

If I am 5′ 4″, how many 70cm pollock would it take to equal my height?

Lastly, on to some, perhaps, cuter and more cuddly creatures than pollock- pets!  Here in the hydroacoustics lab, there is a wall dedicated to pictures of pets owned by the officers, crew, and scientists:

Those are some pretty cute pets left ashore...

Those are some pretty cute pets left ashore…

Clearly, this is a dog crowd!   I did learn, however, that our Chief Scientist, Taina, has her cat (Luna) up there!  Students, do you remember the name of my cat and, what do you think, should I leave a picture of her up here at sea?

Allan Phipps: Let the Fishing Begin! July 28, 2012

NOAA Teacher at Sea
Allan Phipps
Aboard NOAA Ship Oscar Dyson
July 23 – August 11, 2012

Mission: Alaskan Pollock Survey
Geographical Area: Bering Sea
Date: July 28, 2012

Location Data
Latitude: 61°24’39″N
Longitude: 177°07’68″W
Ship speed: 3.8 knots (4.4 mph) currently fishing

Weather Data from the Bridge
Wind Speed: 6.9 knots (7.9 mph)
Wind Direction: 30°T
Wave Height: 2ft with 2-4ft swells
Surface Water Temperature: 8.7°C ( 47.7°F)
Air Temperature: 7.9°C ( 46.2°F)
Barometric pressure: 1005.8 millibar (0.99 atm)

The NOAA Research Vessel Oscar Dyson at port in Dutch Harbor, Alaska.

Science and Technology Log:

Since the main goal of this voyage is the acoustic-trawl survey of the mid-water portion of the Alaskan pollock population, I thought I would start by telling you how we go fishing to catch pollock!  This isn’t the type of fishing I’m used to… Alaskan pollock is a semi-demersal species, which means it inhabits from the middle of the water column (mid-water) downward to the seafloor.  This mid-water survey is typically carried out once every two years.  Another NOAA Fisheries survey, the bottom trawl survey, surveys the bottom-dwelling or demersal portion of the pollock population every year.  I will begin by describing how we are fishing for pollock on this acoustic-trawl survey.

The Oscar Dyson carries two different types of trawling nets for capturing fish as part of the mid-water survey, the AWT (Aleutian Wing Trawl which is a mid-water trawl net) and the 83-112 (a bottom-trawl net that is named for the length of its 83 foot long head rope that is at the top of the mouth of the net and the 112 foot long weighted foot rope at the bottom of the mouth of the net).  One of the research projects on board the Oscar Dyson is a feasibility study that involves a comparison of the AWT and using the 83-112 bottom-trawl net as if it were a mid-water net.  The 83-112 is much smaller than the AWT, so there is concern with the fish avoiding this net and thus causing a reduction in catch.  While the bottom trawl survey acquires good information on the bottom-dwelling pollock using the 83-112 bottom trawl, if they also used this net to sample in mid-water they could help “fill in” estimates of mid-water dwelling pollock in years when the acoustic mid-water trawl survey does not occur.

Scale model of the Aleutian Wing Trawl (AWT) net courtesy of NOAA Scientist Kresimir Williams

When the net is deployed from the ship, the first part of the net in the water is called the cod end.  This is where the caught fish end up.  The mesh size of the net gets smaller and smaller until the mesh size at the cod end is only ½ inch (The mesh size at the mouth of the net is over 3 meters!).

The AWT is also outfitted with a Cam-Trawl, which is the next major part that hits the water.  This is a pair of cameras that help scientists identify and measure the fish that are caught in the net.  Eventually, this technology might be used to allow scientists to gather data on fish biomass without having to actually collect any fish (more on this technology later).  This piece of equipment has to be “sewn” into the side of the net each time the crew is instructed to deploy the AWT.  The crew uses a special type of knot called a “zipper” knot, which allows them to untie the entire length of knots with one pull on the end much like yarn from a sweater comes unraveled.

Cam-Trawl on deck, ready to be “sewn in” to the AWT.

The Cam-Trawl is now “sewn in” to the AWT and is ready to be deployed.

 Along the head rope, there is a piece of net called the “kite” where a series of sensors are attached to help the scientists gather data about the depth of the net, the shape of the net underwater, how large the net opening is, determine if the net is tangled, how far the net is off the bottom, and see an acoustic signal if fish are actually going into the net (more on these sensors later, although the major acoustic sensor is affectionately called the “turtle”).

Close-up view of the AWT scale model to highlight the kite and the turtle that ride at the top of the net. The third wire holds the electrical wires that send data from the turtle to the bridge (courtesy of Kresimir Williams).

Once the kite is deployed, a pair of tom weights (each weighing 250 lbs), are attached to the bridal cables to help separate the head rope from the foot rope and ensure the mouth of the net will open.  Then, after a good length of cable is let out, the crew transfers the net from the net reel to the two tuna towers and attach the doors.  The doors act as hydrofoils and create drag to ensure the net mouth opens wide.  Our AWT net usually has a 25 meter opening from head rope to foot rope and a 35 meter opening from side to side.

This picture shows the A-frame with the two tuna towers on either side. The AWT is being deployed down the trawl ramp on the stern of the ship.

The scientists use acoustic data to determine at what depth they should fish, then the OOD (Officer on Deck) uses a scope table to determine how much cable to let out in order to reach our target depth.  Adjustments to the depth of the head rope can be made by adjusting speed and/or adjusting the length of cable released.

The scientists use more acoustic data sent from the “turtle” to determine when enough fish are caught to have a scientifically viable sample size, then the entire net is hauled in.  Once on board, the crew uses a crane to lift the cod end over to the lift-table.  The lift-table then dumps the catch into the fish lab where the fish get sorted on a conveyor belt.  More on acoustics and what happens in the fish lab in my next blog!

The port side crane is lifting the cod end over to the starboard side where the lift-table will receive this morning’s catch.

Personal Log:

WOW!  What an adventure!!!  So I must get you caught up on some of the happenings thus far.  After a mix-up where my reservation was cancelled on the Saturday afternoon flight from Anchorage to Dutch Harbor and the threat of being stranded in Anchorage for another day, I finally made it to Dutch.  The weather cooperated (which is not the case more often than not), and we landed on Dutch Harbor after a quick refueling stop in King Salmon.  Since we landed after 8pm, we went straight to one of the few restaurants in Dutch Harbor and had a late dinner before heading to the Oscar Dyson for the night.

My flight after landing in Dutch Harbor, Alaska!

Sunday morning, we went with several of the scientists out to Alaska Ship Supply to get some gear.  I picked up my obligatory “Deadliest Catch” shirt and hat as all tourists do here in Dutch Harbor. We made three trips to the airport throughout the day to see if some of the science gear and luggage came, but came back disappointed.  On one of our trips to the airport, we had lunch at the airport restaurant.  I had Vietnamese Pho, which is a beef noodle soup, but it wasn’t nearly as good as the Pho my wife makes. :) We also drove up the “Tsunami Evacuation Route” to an overlook where we could see all of Dutch Harbor and the town of Unalaska.  Later, we drove around Unalaska and stopped to check out some tidal pools on our way back to the Oscar Dyson.  In the afternoon, we checked out the World War II museum that was absolutely fascinating!  I did not know Dutch Harbor was bombed by the Japanese and that so many American soldiers were stationed in the bunkers surrounding the harbor.  For dinner, I had black cod (sablefish) at the Grand Aleutian Hotel.  Yummy!

Overlooking Dutch Harbor after driving up the Tsunami Evacuation Route.

Monday we embarked on our adventure shortly after noon.  We had to leave the dock because another ship was scheduled to offload there in the afternoon.  The scientists’ equipment arrived on a late Monday morning cargo flight, but they didn’t make it to the ship on time!!! We couldn’t go to sea without them, so we deployed the “Peggy D” to go pick them up and bring them aboard!

The Peggy D brings our scientists Rick and Kresimir with their long-awaited research equipment to the Oscar Dyson so we may head out to the Bering Sea!

Once we had our missing scientists, we left the safety of Dutch Harbor and ventured into open water.  On our way, we saw dozens of humpback whales!  None of the whales breached (jumped out of the water), but several of them fluked (dove and put their tail out of the water).

A couple of humpback whales spotted as we were leaving Dutch Harbor.

We started our day and a half journey to get to the starting point of our survey transects (the end point of last month’s survey).  On our trip out, we experienced 6 to 10 ft seas and a 25 knot wind.  It was a “gentle” welcome to the Bering Sea, but I struggled to get my sea legs underneath me.  Meclizine is great motion sickness medication, but it sure knocked me out.  I feel better now that I am not taking anything and am used to the rocking deck.  While we made our way to our first transect, we had a couple of emergency drills.  Here I am with fellow Teacher at Sea, Johanna, in our immersion suits as we completed our abandon ship drill.

Relaxing in the lounge after putting on our “gumby” suits.

On Wednesday morning, we began our first transect and did our first trawl along the transect (more on that later).  I learned how to work in the fish lab collecting biological data on the catch we brought on board.  I have been struggling to adjust to both my shift, which is 4am to 4pm, and the fact that the sun sets around 1am and rises at about 7am.

In the fish lab processing Pollock! Did someone order fish-sticks?

Thursday morning I woke on time and observed the survey scientists and crew deploying the CTD (Conductivity, Temperature, Depth) rosette from the hero deck (on the starboard side).

Skilled Fisherman Jim is assisting with deploying the CTD.

We also had beautiful clear skies and I was able to see Venus and Jupiter.  At sunrise, I saw the GREEN FLASH!!!  It was a beautiful start to the day.

A Bering Sea sunrise!

We processed one mid-water AWT (Aleutian Wing Trawl) trawl that was all pollock, then switched to the 83-112 bottom trawl net (83 foot long head-rope and 112 foot long foot-rope) and pulled up a lot of jellyfish with our pollock.

Last night, I finally got a really good night sleep!  This morning (Friday), I watched the CTD deployment again and learned more about the data being collected (more on this later).  No spectacular sunrise this morning as it was the typical gray, foggy weather.  I went up and spent some time on the bridge and Chelsea, our navigator/medic, taught me a lot about the instrumentation used for navigating the ship.  There sure is a lot of technology on board!!!

A picture of the helm with some of the displays the OOD (Officer on Deck) uses to navigate the ship.

From the bridge, we saw a pod of Dall’s Porpoise feeding, splashing around, and moving fast!  We processed another AWT trawl of pollock that had quite a few herring mixed in.  We traveled further into Russian waters than originally anticipated as we tried to identify the northern boundaries of the pollock population to get the best picture of the entire pollock range.  We spotted a huge Russian trawler from the bridge!

A Russian trawler! I took this picture through the lens of the CO’s (Commanding Officer) binoculars.

We then headed south again towards American waters, but needed to do a quick water column profile test.  Since we did not want to stop to drop the CTD again, I got to deploy a XBT (Expendable Bathythermograph)!  After all the talk about safety briefings, the use of ballistics, and outfitting me with every piece of safety gear we could muster, I got ready to fire the XBT!!!  Turns out, when you pull the firing pin, the XBT just slides out of the tube… no fireworks, no big bang… just a small kurplunk as the XBT enters the water.  We all had a good laugh at my expense.  See, scientists know how to have fun!

Safety first!!! All decked out for the “fireworks” of shooting the XBT. My “was that it?” face says it all…

WOW!  So I have just scratched the surface of our voyage thus far!  Next time, I will give you a snapshot of what life was like aboard the ship.

Story Miller, July 20, 2010

NOAA Teacher at Sea: Story Miller
NOAA Ship: Oscar Dyson

Mission: Summer Pollock III
Geographical Area: Bering Sea
Date: July 20, 2010

Time: 1240
Latitude: 53°51N
Longitude:166°34W
Wind: 7 knots (approx. 8.055mph)
Direction: 202° (SW)
Sea Temperature: 9.22°C (approx. 48.596°F)
Air Temperature: 9.82°C (approx. 49.676°F)
Barometric Pressure (mb): 1023.8

Scientific Information

Figure 1: View of the low fog, clouds and sunset in Dutch Harbor the night of the delay.

What Is NOAA and How Can You Get Involved?
NOAA stands for the National Oceanic and Atmospheric Association and is part of the United States Department of Commerce. NOAA is involved around the world and there are many different avenues one could become involved with. For example, some people are involved in forecasting the location of the next hurricane strike, which means that you could be responsible for saving the lives of people living in those areas. If climate change is of a particular interest, you could aid in the monitoring of global weather systems to make climate predictions for the future. If ecological studies suit you, a job with NOAA could involve collecting data from costal environments to continue efforts of preserving healthy ecosystems. Perhaps your studies and data analysis would aid in the critical decision making processes of businesses around the world, such as creating and enforcing policies for the fisheries industry to maintain its resources for the future.  Mapping is equally important and part of your experience with NOAA could involve creating or enhancing navigational data to aid in the protection of ships and prevent potential accidents. Finally, perhaps you are interested in commanding a NOAA ship or piloting a NOAA aircraft. In that case, you could become part of the NOAA Corps.

The Mission

The primary mission of the Oscar Dyson is the Walleye Pollock survey, which consists of conducting Acoustic Surveys and Fishery Survey Trawls. The acoustic survey relies on sonar waves that are powerful enough to detect fish at different depths. Once the fish is located on the sonar screen, the trawl net is then accurately deployed to a specific depth depending on where the targeted fish species are located. This depth can range from 16 meters from the surface all the way down to 3 meters from the bottom.  The net is then hauled onto the ship’s aft deck and the contents are spread on the table in the lab for sorting and identification. Different species, such as the Walleye Pollock, will be measured for size, sex, and age before being released overboard. Some other species like Pacific Cod and Arrowtooth Flounder will be collected for additional studies.

Delays, Delays!

Monday, July 19th appeared to be a rare, sunny day in Dutch Harbor for most of the afternoon. We were scheduled to leave Dutch Harbor at 1500h but due to baggage problems for those who recently arrived in Dutch Harbor, we were delayed until the next day. Because of the short airstrip in Dutch Harbor, the sizes of the airplanes are smaller than those of regular airports. Currently Pen Air uses SAAB Turboprop airplanes. These planes are small and hold about thirty passengers. They are typically used for small air carriers for short commutes.  Another critical factor involved with flights is weight. For every passenger, think of the additional weight of all the bags each person has. Most people fly with one or two bags, each weighing 50lbs or less and in our case, some people also had additional bags carrying scientific equipment.

Figure 2: A typical foggy day in Dutch Harbor, Monday, July 19th, 2010

Weight in an airplane causes the plane to use more fuel and smaller airplanes cannot carry as much fuel as the other airplanes, such as Boeing 737 aircraft, commonly used for longer commutes by larger airlines. Because of the distance between Anchorage and Dutch Harbor, full flights generally need to make a stop in the small villages of King Salmon or Cold Bay to refuel. Other difficulties faced by the airport in Dutch Harbor are that the airstrip is a “daylight only” landing zone and the weather can be quite hazardous. Winds reaching up to 90 mph are not uncommon and in the summer, low fog becomes a visibility issue. If the pilots do not have a specific range of visibility, they cannot land. Therefore, the necessity of refueling in Cold Bay or King Salmon is critical because many times when the plane reaches the airport and hazardous weather conditions are preventing a safe landing, the airplane must have enough fuel to circle the airport in hope for a sliver of time when landing conditions are safe and, if necessary, enough fuel to fly all the way back to King Salmon or Cold Bay. Again, weight is an issue in the fuel consumption of an airplane and therefore, on full flights, the airplane must sometimes “bump” bags, which means that sometimes your checked bag will not make it on the flight you are on and will be scheduled on a later flight. This of course isn’t a bad plan except that the weather in Dutch can change from one extreme to the next in a matter of fifteen minutes. In our case, to add to the difficulty of getting our bags, it was explained to us that because the air had become warmer, it lessened the lift on the airplane which was another reason why the planes did not carry very many bags that day. With all these important technicalities, one could maybe understand why flying into Dutch Harbor can be difficult. Therefore, some people have successful flights and others experience the “flight to nowhere” which involves flying part or the entire three hours to Dutch Harbor, circling or waiting in Cold Bay, and then flying back to Anchorage. One could say that you are not a local until you have experienced this situation a few times!

Personal Log:

My first day on the boat proved to be interesting as I quickly learned my way around the ship. I sometimes make the analogy of myself being like a rat in a maze trying to find the cheese. In a way it is accurate because the cook on board has made some fantastic dinners and I’ve been successful at finding the mess hall by simply following my nose! For supper on Monday night, we had a buffet-style dinner and I was pleasantly surprised with the menu as I helped myself to prime rib and king crab legs!

Figure 3: Me in front of the Oscar Dyson, Monday, July 19th, 2010 (notice the extreme weather change!)

On Tuesday, we were able to get underway at approximately 1300. Before pulling away from the dock, we needed to test our FRB (Fast Rescue Boat) to make sure it was functional in the possible event of an emergency. Once we knew the FRB was functional, we hauled it back onto the boat. As soon as we began to move, I went to the flying bridge (the highest deck on the ship) to catch a glimpse of Dutch Harbor and to watch the local birds sitting on the water. Most of the birds I saw were tufted puffins. I always find them amusing because if you get near them when they have eaten too many fish, they try to fly away but their belly is too heavy. Therefore they simply skim over the water, wings flapping intensely, and bellies dragging over the top of the water!

Figure 4: Lead Fisherman Dennis Boggs and Skilled Fisherman Mike Tortorella testing the FRB

Some advances in healthcare that I am extremely excited about is that I have found a seasickness medication that does not knock me out in under 5 minutes and that works for a long period of time. Thank you Meclizine!
Currently we are underway and have approximately 381 miles northwest to travel before we make our waypoint which will take approximately 28 hours. As of right now, my job has been to get acclimated to the ship. Work will begin Thursday at sunrise, about 0700).  My current shifts will run from 0400h to 1600h each day. I cannot wait to begin the first part of my assignment!

Animals Spotted By Me Today:
Blackfooted Albatross
Tufted Puffin
Seagull
Sea Otter
Fur Seal

Something To Ponder:
Regarding NOAA fish surveys, such as the Pollock Survey I’m participating in, what impacts would the scientific information collected have on the fishery industry regarding revenue and long term success?

Amanda Peretich: Awesome Acoustics, July 13, 2012

NOAA Teacher at Sea
Amanda Peretich
Aboard Oscar Dyson
June 30, 2012 – July 18 2012

Mission: Pollock Survey
Geographical area of cruise:
Bering Sea
Date:
July 13, 2012

Location Data
Latitude: 59ºN
Longitude: 174ºW
Ship speed: 11.7 knots (13.5 mph)

Weather Data from the Bridge
Air temperature: 7.3ºC (45.1ºF)
Surface water temperature: 7.6ºC (45.7ºF)
Wind speed: 4.3 knots (4.9 mph)
Wind direction: 12ºT
Barometric pressure: 1010 millibar (1.0 atm, 757.5 mmHg)

Science and Technology Log

How sonar works: energy (sound) waves are pulsed through the water. When it strikes an object, it bounces back to the receiver. (from http://www.dosits.org/)

How sonar works: energy (sound) waves are pulsed through the water. When it strikes an object, it bounces back to the receiver. (from http://www.dosits.org/)

Before stepping onto the Oscar Dyson, I wasn’t quite sure about much of the science going on. Did they just put the nets in the water every so often and hope to catch some fish? Carefully lean over the side of the ship saying “here fishy fishy” with the hope that the pollock would find their way into the net? Neither of these scenarios is correct (good thing I’m not actually a fisherman!). So today’s lesson is going to be all about what the chief scientist actually uses to find fish: hydroacoustics (hydro meaning water and acoustics meaning sound). This also involves SONAR, which is short for SOund Navigation And Ranging.

Fishfinding Basics

Fishfinding basics.

If you’ve ever been on a smaller boat, yacht, fishing vessel, or the like, you may have seen something called a fishfinder. The basic concepts are the same as what is happening on the Oscar Dyson. An echosounder sends a pulse of energy waves (sound) through the water. When the pulse strikes an object (such as the swim bladder in fish), it is reflected (bounced) back to the transducer. This signal is then processed and sent to some sort of visual display.

Swim Bladder

Swim bladder in a fish.
(from https://www.meted.ucar.edu/)

The Oscar Dyson uses acoustic quieting technology where the scientists can monitor fish populations without altering their behavior. The Scientific Sonar System and various oceanographic hydrophones (underwater microphones) are raised and lowered through the water column beneath the ship on a retractable centerboard. This is important so that the transducers can be lowered away from the flow noise generated by the hull, which in turn will improve the quality of data collected. In addition, there is a multibeam sonar system located on the forward hull. Ultimately the hydroacoustic data is all used as one piece to the puzzle of measuring the biomass of fish in the survey area.

OD acoustics

The different sonar signal transmitter/receivers (transducers) used on this leg of the pollock survey and their location on the ship.

Neal at work

Chief scientist Neal working away in the Acoustics lab. The second screen from the left on the upper row is showing the information from the ME70 multibeam.

So how does this all work when we are looking for fish? The chief scientist (Neal on the 0400-1600 watch) or another scientist (Denise on the 1600-0400 watch) will spend a lot of time analyzing the various computer screens in the acoustics lab, which has been affectionately termed the “cave” (no windows). They are looking at the information being relayed from both the multibeam and the EK60.

What is a multibeam? The Oscar Dyson has the Simrad ME70 scientific multibeam echosounder. It is located on the hull (underside) of the ship on the front half and sends 31 sonar beams per second down to the bottom of the sea floor.

Multibeam

Multibeam echosounder.
(from http://www.simrad.com/)

Aft of the multibeam (on the centerboard) are the five Simrad transducers. It may seem confusing, but hopefully I can walk you through a teensy little bit of how it works when we are looking to trawl for fish.

EK60 Transducer

Information from the EK60 transducer at 18kHz (top) and 38kHz (bottom).

Information from the EK60 echosounder is displayed on the far left screen in the acoustics lab while information for the ME70 multibeam is displayed on the next screen. The darker patches are showing that there are fish in that area. When the scientist first starts to see a good amount of fish, they will “mark” it and keep watching. If the screen fills up with fish (as in the EK60 image), the scientist will call upstairs to the bridge and tell them where to head back to on the transect line to start trawling. Depending on the location of the fish in the water column, it may be a bottom trawl (83-112 net), a midwater trawl (AWT net), or a methot trawl. Side note: the 83-112 midwater comparison trawl that I’ve mentioned before is done almost immediately after an AWT midwater trawl to compare the fish caught in a common area.

ME70 Multibeam

Information from the ME70 multibeam. You can determine the sea floor depth and there are five narrow beam slices from the mid-section of the multibeam (of the 31 different beams that span 120 degrees) displayed on screen.

Neal on bridge

Chief scientist Neal up on the bridge.

Then the scientist will head upstairs as the deck crew is preparing the net. One of the many sensors attached to the net is called the FS70 fishsounder or “the turtle”, and it is only used during trawls (because it is attached to the headrope). The scientist can “watch” the fish swimming under the ship using the EK60 information combined with the information from the fishsounder. The yellow “turtle” on the right in the image shows how the FS70 is flying in the water. You want minimal pitch and roll and for the front of it to be facing the back of the ship. This way, we can “see” the fish as they are going through the net. The officer of the deck and lead fisherman or head boatswain can adjust various things to keep the turtle in the right orientation. The middle image below is constantly changing on the screen in the bridge as the sonar is sweeping back and forth, so you can almost watch the individual fish enter the net. It was interesting to watch the delay between when you would see the fish from the EK60 (on the left) and when you saw them with the FS70 (middle).

Trawl Fishsounder

Display screens on the bridge used during a trawl.

Once the scientist is satisfied that enough fish have been caught for a sufficient sample size, the net will be hauled back and the acoustics work is done for just a little bit (giving Neal some time to grab some well-deserved coffee and the rest of us time to get our rain gear on to process the fish).

So some of the questions I had asked (that don’t really fit nicely in the information above):

Why do we use different frequencies in the acoustic studies?

Frequency Wavelength

Relationship between frequency and wavelength. (from http://emap-int.com)

This ties right back in to chemistry (and other sciences) with an equation and the relationship between frequency and wavelength (yay!). Basically there is an inverse relationship which means that at a high frequency there is a smaller or shorter wavelength (wavelength is the distance for peak to peak of a wave). At a low frequency, there is a higher or longer wavelength.

At a low frequency, you will see only see things that are larger, like pollock, whereas you will see very small things like krill and zooplankton at higher frequencies. Having information from both types of frequencies is necessary to complete the scientific research on the Oscar Dyson.

Single Fish

Traveling at 1 knot, showing single fish from EK60 sonar.

Is it possible to see a single fish?
Yes! From sunset to sunrise, the Oscar Dyson doesn’t actually travel the transect lines. This is because the pollock behave differently during darkness than during the day. So instead of traveling between 11 and 12 knots (which is what happens between trawls), it’s almost like the boat is just sitting around for a couple of hours. But during this time, since the boat isn’t moving along quickly, it’s possibly to see individual fish on the sonar as shown in the image.

Hydroacoustics

Hydroacoustic surveys can involve any number of different types and locations of the transducers. (from http://btechgurus.blogspot.com/2012/06/sonar.html)

Personal Log
Today is Friday the 13th but it was far from unlucky – I finally saw something out in the water other than fog: a boat! Again, all good sightings seem to come from up on the bridge, so I’m thankful for Lieutenant Matt for allowing me to ask a billion questions while I’m up there and teaching me more than I ever thought my brain could hold. He has all of the qualities of a great teacher, which is nice to see.

Ship

The ship we saw up on the bridge this morning from about 5 nautical miles away (left), on the sonar (middle), and through the binoculars (right).

Dancing in the fish lab on the Oscar Dyson

Neal and I dancing while waiting for the fish!

Highlight from the other day? Chief scientist Neal finally dressed out in his Grundens (rain gear) and came to help process a catch in the fish lab! While waiting, he even took a quick second to dance in the doorway (we were “Dougie”-ing) to my music that was playing over the speaker system.

References
NOAA Oscar Dyson flier
NOAA Oscar Dyson Ship Electronics Suite
HTI Sonar
Wikipedia: Sonar
Simrad

Lesley Urasky: Do You See What the Pisces “Hears”?, June 22, 2012

NOAA Teacher at Sea
Lesley Urasky
Aboard the NOAA ship Pisces
June 16 – June 29, 2012

Mission:  SEAMAP Caribbean Reef Fish Survey
Geographical area of cruise: St. Croix, U.S. Virgin Islands
Date: June 22, 2012

Location:
Latitude: 18.5472
Longitude: -65.1325

Weather Data from the Bridge:

Air Temperature: 28.6°C (83.5°F)
Wind Speed:  9 knots (10.5 mph), Beaufort scale: 3
Wind Direction: from SE
Relative Humidity: 77%
Barometric Pressure: 1,014.80  mb
Surface Water Temperature: 28.1°C (82.6°F)

Science and Technology Log

Another aspect (much more technical) of the scientific research conducted on this cruise is the collection of acoustic data.  This field is continually evolving as the detection resolution improves allowing scientists to more precisely identify fish.  This has been used with more success in fisheries farther north because the schools of fish are more likely to be monospecific (a single species).  However, the technique still needs improvement in warmer waters where the fish assemblages tend to be multi-specific (having a much greater variety of fish).

General idea behind an acoustic sounder being used to detect fish. (Source: www.biosonicinc.com)

This field of study is called Hydroacoustics (hydro- means water, and acoustics refers to sound).   It is the science of  how sound moves through water. Leonardo da Vinci noticed how sound travels through water in 1490.  He noticed that, “If you cause your ship to stop and place the head of a long tube in the water and place the outer extremity to your ear, you will hear ships at a great distance from you.” (Urick, Robert J. Principles of Underwater Sound, 3rd Edition. New York. McGraw-Hill, 1983.)  World War I helped promote innovation in the field, especially with the need for anti-submarine detection devices (Wood, A. B., From the Board of Invention and Research to the Royal Naval Scientific Service, Journal of the Royal Naval Scientific Service Vol 20, No 4, pp 1-100 (185-284)).

Hydroacoustic instruments utilize SOund Navigation and Ranging, more commonly referred to as SONAR.  The ship Pisces is equipped with a system located on the center board; this is a flat structure that can be raised/lowered through the water column beneath the center of the ship.

Line drawing of the NOAA ship Pisces showing the location of the center board.

The system used is a sonar beam that is split into quadrants.  This instrument is used to assist in determining fish abundance and distribution.  The premise is relatively simple: an echo sounder transmits a pulse of energy waves (sound), when the pulse strikes an object, it is reflected (bounced) back to the transducer.  The echo sounder is then processed and sent to a video display.  This is the same general process behind the recreationally available fishfinder.

Acoustic beam split into quadrants (Source: http://www.htisonar.com

A short burst of energy is focused into a narrow beam.  When this beam encounters an object such as a fish, a school of fish, plankton, or other object, some of the energy bounces back up through the water to the transducer.   It is the detection of these reflections that allow scientists to determine location, size, and abundance of fish.  These reflections show up on our video monitor.  These measurements are combined with groundtruthed data (for example, fish collected in the field, camera images).

One of the difficulties in data interpretation is that often, the signals that appear on the computer monitor have false readings.  This is a result of the sound wave bouncing multiple times.  It travels to the bottom from the transducer, strikes an object, returns to the ship, bounces off the ship back toward the bottom, strikes another object, and is detected yet again.

Real-time annotated echogram at sampling site.

The Pisces is actually home to one of six multi-beam acoustic instruments in the world.  Of the six in existence, NOAA has five of them.  The benefit of running a multi-beam instrument is that each beam can be set to measure a different frequency (kHz), thus enabling detection of many more features (different species of fish, etc.)

Scientific multibeam echo sounder (Source: www. simrad.com)

Personal Log

Last night the crew of the Pisces carried out a task that they don’t normally perform.  The Pisces was created for fisheries research projects – it focuses on collecting fish samples either by bandit reel, longline, or trawling.  This particular operation was to deploy the anchor for a buoy that will be attached at a later date.  When the buoy is ready to be attached, another vessel will bring it out to the site and divers will go down to the anchor to make the final attachment.

The anchor consists of a huge rebar-reinforced concrete block with a very long chain that has marker floats attached at the end.  Logistically, this took some planning; the A-frame had to be raised and the anchor lifted with the Gilson winch with a 1″ spectra line (has an enormous tensile strength).  The gate to the ship’s ramp was lowered and the A-frame (or as the deck hands call it, the “Tuna Tower”)  repositioned so the anchor was hanging over the water.  The rope holding the anchor, chain, and float was cut through, and the anchor plunged to the ocean bottom.  Again, the crew made the operation go smoothly and demonstrated their ability to complete unexpectedly assigned tasks.

Today was a slow fishing day – no fish at all.  Without any fish to “work up” (collect samples from), the day goes more slowly and we have more down time.  With the extra time, I had a chance to interview Kevin Rademacher, the Chief Scientist on the cruise.

LU: What is your official job title and what are your job duties?

KR: I’m a Research Fisheries Biologist.  I work for the Reef Fish Unit at the NOAA Fisheries Lab in Pascagoula, MS.  I am the Senior Tape Reader/Reviewer, in charge of the readers that analyze  the video data we collect from Reef Fish Surveys.  I also help plan, organize, and run the surveys.  Additionally, I participate in trawl surveys and anything else the lab needs done.

LU: When did you first become interested in the ocean and marine sciences?

KR: I guess that would have been when I was really young.  There is a photo from the Panama City, Florida newspaper, two weeks after I was born with my parents pulling me in a homemade wagon along the beach!  I knew in junior high school that I wanted to be a cross between Jacques Cousteau and Marlin Perkins of Mutual of Omaha’s Wild Kingdom.

LU: It’s such a broad field; how did you narrow your focus down to what you’re currently doing?

KR: I got lucky and kind of fell into reading underwater videos at the initial stages of the project and fell in love with being the proverbial “fly on the wall”! It has allowed me to see the fish in their natural  habitat, different color phases, behavior, etc.

LU: If you were to go into another area of ocean research, what would it be?

KR: Marine Mammal Studies.  After college I trained dolphins and sea lions and put on shows with them for a local Oceanarium on the Mississippi Gulf Coast.

LU: What is the biggest challenge in your job?

KR: Communicating with people and writing papers.

Ariane Frappier and Kevin Rademacher reviewing a dichotomous key in order to determine the species of a fish we caught.

LU: What do you think is the biggest issue of contention in your field?

KR: The impression that commercial fishermen have regarding the work we do to regulate the fisheries they work in.

LU: What are some effects of climate change that you’ve witnessed during your career in fisheries research?

KR: The decline of coral reefs and overfishing of some species.

LU: In what areas of marine science do you foresee a lot of career paths and job opportunities?

KR: Ecosystem management and data modelers.  There has also been a decline in taxonomists over the past few decades.

LU: How would you explain your work to a layperson?

KR: I use underwater cameras to help assess populations of reef fish, especially snappers and groupers.  The data collected is used to manage those fisheries.

LU: If a high school student wanted to go into your field of study/marine science in general, what kinds of courses would you recommend they take?

KR: Math, Biology, Chemistry, and any other science courses available.

LU: Do you recommend students interested in your field pursue original research as high school students or undergraduates?  If so, what kind?

KR: Most definitely! Whatever they are interested in would be beneficial.

Well, only two more days left with the scientists before we pull into San Juan, Puerto Rico.  We have 17 more daytime sites to sample and then this survey will be over.  The scientific crew will be flying home on the 25th, and once home, their work will really begin.  Back in the lab, they will be analyzing the data and reviewing the video.  Some of them will be going back out on other cruises.  Kevin Rademacher will be going out on another reef fish survey in the eastern Gulf of Mexico.  It is currently delayed because of the potential formation of tropical storm Debby.  Joey Salisbury has a couple more; he will be going on a longline cruise and then another reef fish survey, both of which will be in the Gulf of Mexico.  Arian Frappier will be heading off to begin a masters program in marine systems and coastal studies at Texas A&M Corpus Christi.

After a day’s shore leave in San Juan, I’ll continue on to Mayport on the Pisces.  During this time, I’ll focus on the crew members and their jobs.  The cruise will definitely take on a different feel at this point, but it will give me an opportunity to explore other ocean related careers.

Alexandra Keenan: Singing Whales, June 23, 2012

NOAA Teacher at Sea
Alexandra Keenan
Onboard NOAA Ship Henry B. Bigelow
June 18 – June 29, 2012

Mission: Cetacean Biology
Geographical area of the cruise: Gulf of Maine
Date: June 23, 2012

Weather Data from the Bridge:
Air temperature: 14.4° C
Sea temperature: 13.3° C
Wind speed: 10.5 knots
Wind direction: from the SW

Science and Technology Log:

Whales are social creatures with a remarkable ability to communicate with one another over long distances using sounds. Male humpback whales, for example, can sing for days on end over mating grounds to attract the ladies, or over feeding grounds such as the ones on Georges Bank (where we are!) The acoustic behavior of sperm whales may even provide for distinct cultures within the species.

Listen: Song of a humpback whale (courtesy Denise Risch)

Given these vocalizations, it is possible to monitor the distribution and behavior of acoustically active marine animals using special recording units called “marine autonomous recording units” (MARUs). For the past few days, we have been zig-zagging and loopty-looping around Georges Bank to retrieve several of these MARUs (track our ship’s course here).

MARUs are little buoys designed to sit on the ocean floor and record all sounds within a certain range of frequencies. The MARUs we retrieved during this cruise have been on Georges Bank since the March cruise on the Delaware II (see Chief Scientist Allison Henry’s blog post).

To retrieve a buoy:

1. An acoustic signal (a sound) is sent out from a speaker lowered into the water that basically says to the buoy, “Hello! Are you there?” Listen: Signal used to contact buoy

pop-up buoy retrieval

Bioacoustician Denise Risch sends a signal to the MARU.

2. The buoy can then respond with another acoustic signal, “Yup!”

listening for the pop-up buoy

Research analyst Genevieve Davis and intern Julia Luthringer listen for a response from the MARU.

3. Upon hearing confirmation that the buoy is indeed in the area, the bioacoustician can send another signal to the buoy telling it to burn the wire anchoring it to the sandbags on the ocean floor.

4. The buoy is free! It floats to the sea surface and is retrieved from the side of the ship.

Denise Risch, Genevieve Davis, and Julia Luthringer wait for the ship to approach the MARU (small yellow dot in ocean).

5. Data is retrieved from flash memory on the buoy for further analysis.

MARU

MARU ready for data retrieval.

What will these MARUs be able to tell bioacousticians (scientists that study sounds produced by living organisms)?

Lots!  Using passive acoustic monitoring (recording the sounds that marine mammals make), scientists can study the distribution of acoustically active mammals and can couple distribution data with environmental measurements of the area to identify relationships between conditions on the ocean and acoustic activity. Scientists can also distinguish whale species based on their sounds, so certain species of whale can be monitored.

Physics break: Why do you think whales have evolved to use sound rather than sight or smell to communicate underwater?

Personal Log:

I have been amazed by the amount of maintenance being done while we are underway. Even with a relatively new ship like the Bigelow, there is always something to be done, whether it be grinding away at the deck for subsequent repainting or fixing a malfunctioning pump.

Maintenance on the Bigelow

Deck crew member Tony repaints the deck after grinding off the old paint while we are underway.

We spend most of our days out on the fly bridge watching for whales, and mostly we see whales.

whale watching

Equipment used for watching for whales from the flybridge.

However, once in a while a shark, turtle, or mola mola floats by. I really get a kick out of the mola molas. They look like they could be the subject of a Pokemon trading card– a big flat fish head with fins sticking out. They eat jelly fish and have few natural predators. Adults weigh an average of 2200 lbs!

mola mola

The other-worldly mola mola.

A short video of one in action below:

Finally, I wanted to introduce everyone on the science team for this cruise:

aglow following a blue whale sighting

From left to right: Me, Scientist Pete Duley, Bioacoustician Denise Risch, Chief Scientist Allison Henry, Scientist Jen Gatzke, Research Analyst Genevieve Davis, and Intern Julia Luthringer (photo courtesy CO Zegowitz)

Lindsay Knippenberg: Acoustics Day! September 13, 2011

NOAA Teacher at Sea
Lindsay Knippenberg
Aboard NOAA Ship Oscar Dyson
September 4 – 16, 2011

Mission: Bering-Aleutian Salmon International Survey (BASIS)
Geographical Area: Bering Sea
Date: September 13, 2011

Weather Data from the Bridge
Latitude: 56.91 N
Longitude: -169.08 W
Wind Speed: 10.07 kts
Wave Height: 4 – 6 ft
Surface Water Temperature: 6.5 C
Air Temperature: 7.5 C

Science and Technology Log

The Oscar Dyson uses several different types of sonar to get the best image of what is beneath the ship.

The Oscar Dyson uses several different types of sonar to get the best image of what is beneath the ship.

Today I learned about acoustics with Paul. The Oscar Dyson is one of NOAA’s newer ships and has a hull-mounted sonar system which uses sound waves to “see” what is underneath the ship. The Oscar Dyson was also built to have a low acoustic signature and be “quiet” in the water. This is helpful to the scientists using acoustics to study fish onboard the Dyson because the fish don’t hear the ship and swim away. On our cruise the acoustics data is used to get a picture of where there is life in the entire water column. For the most part we have just been trawling on the surface, but the ocean is much deeper and there could be a lot more life underneath our nets that we will never catch. If we get very few fish in our nets, it could mean that the fish are just at a deeper depth and not that there are not any fish in that area. Since the scientists are getting a better picture of what is really going in that ecosystem, they can make more accurate stock assessments. All throughout the cruise I have been curious about the images displayed on the screens in the acoustics room and on the bridge. Today I would finally learn what they were all about.

Since the sonar is attached to the bottom of the boat, the top 14 meters aren't seen in the images. To solve that problem, a sonar transducer is lowered over the side to get the top 14 meters when we at station.

Since the sonar is attached to the bottom of the boat, the top 14 meters aren't seen in the images. To solve that problem, a sonar transducer is lowered over the side to get the top 14 meters when we at station.

Basically how acoustics work is that a sound or ping is sent from the ship and it travels through the water. When it hits something in the water column or the bottom of the ocean it bounces back and the ship’s echosounder records the length of time that it took for the sound wave to travel there and back. Depending on the temperature and depth of the water, the pings are sent at different time intervals and pulses. The pings can also be sent at different frequencies to “see” different types of organisms. For instance zooplankton can be viewed best at one frequency and jellyfish can be viewed best at another frequency. As the sound waves are returning to the vessel, the computer translates the returning sound waves into images for the scientists to analyze.

A sonar image at dawn. The dark red line at the bottom of the screen is the ocean floor. Notice all the greens and blues at the top of the water column. Those are pollock.

A sonar image at dawn. The dark red line at the bottom of the screen is the ocean floor. Notice all the greens and blues at the top of the water column. Those are pollock.

On our cruise Paul is comparing the sonar signatures produced by the different organisms under the boat to what we are actually catching in the nets. The use of acoustics technologies for stock assessments is fairly new and individual species can’t be recognized by the sonar images, but Paul can use the images to detect if an area will have a greater density of organisms. We are also selecting several locations between stations to do mid-water trawls. Paul selects areas that have a high density of organisms underneath the depth that our surface trawl nets reach and we do a mid-water trawl. He then compares what we find in the trawl to the sonar signatures that he saw in the images to see if he can find any patterns between specific species and sonar signatures. It will be amazing if some day fisheries biologists will be able to assess the stock of fisheries by using sonar instead of net trawls which are a lot more work and often result in the death of the fish.

Personal Log

Today's weather after the two low pressure systems had entered the area. The weather was pretty crappy the last two days, but today it is beautiful.

Today's weather after the two low pressure systems had entered the area. The weather was pretty crappy the last two days, but today it is beautiful.

We have had several lo- pressure systems blow through during our cruise and so far we have had two gale warnings. The first one occurred when we had only been out to sea for a day so it was easy to head back in to Dutch Harbor. The last one occurred a couple of days ago and we were too far out into the Bering Sea to turn back. We had no choice but to ride it out. Two low-pressure systems were colliding and the Bering Sea turned into a washing machine. There were consistent 10 – 13 ft waves coming from one direction, large 20ft swells coming from another direction, and the occasional 8 – 10 ft wave coming from a different direction. The ship just kind of bobbed from side to side and up and down and we were all along for the ride. Thank goodness I didn’t get sick, but I definitely didn’t sleep well.

Face to face with some angry seas.

Face to face with some angry seas.

I was also amused by how life went on for everyone onboard the ship. Dinner was hilarious as everyone held onto their dishes and your chair moved from side to side with the waves. Walking around was pretty funny too. There was no way that you could walk in a straight line. I would choose something to grab onto, walk another couple of steps, and then grab onto something else. As I tried to sleep at night I could hear the things that we had thought we had secured roll around the room. Who knew that a roll of paper towels could make so much noise? The curtain on my bed was making me crack up because it would roll open with one wave and close shut with another. It just kept opening and closing all night and there was nothing that I could do about it but laugh. Thankfully by today the seas had calmed down significantly and the sun is actually out.

Francesco was a lost shorebird who found his way to our ship in the middle of the Bering Sea.

Francesco was a lost shorebird who found his way to our ship in the middle of the Bering Sea.

There was one casualty though, and that was Francesco. Francesco was a shorebird, an American Pipit, that was blown way off course during the storm. He ended up cold and hungry on our back deck last night. We were able to catch him and we put him in a warm box with some dead flies, water, and crackers. He managed to eat and drink, but he was a juvenile and had very little body fat. He was pretty much skin and bones. He lasted until this afternoon and when we went to check on him, he was dead. We gave him a burial at sea and were reminded that the Bering Sea is a harsh, harsh environment.

Cathrine Fox: Issue Twelve: Better than any alarm clock

NOAA TEACHER AT SEA
CATHRINE PRENOT FOX
ONBOARD NOAA SHIP OSCAR DYSON
JULY 24 – AUGUST 14, 2011


Mission: Walleye Pollock Survey
Location: Kodiak, Alaska
Date: August 11, 2011

Weather Data from the Bridge
Latitude: 57deg 22.630N, Longitude: 152.02° W
Air Temperature: 13.6° C
Water temperature: 9.0° C
Wind Speed/Direction: 12kn/240°
Barometric Pressure: 1020.1
Partly cloudy (5%) and sun

Science Log:

Stern of the Oscar Dyson

Stern of the Oscar Dyson

Somewhere back in my family history there must have been a fishmonger, because I’ve been channeling something or someone. The entire process of watching the acoustic footprint of the ocean under the ship, deciding where to physically sample (trawl) populations, and then seeing and processing the fish that live 100 meters or more below us? Fascinating. Add to this camera drops to get snapshots of the ocean floor (more amazing footage this morning), and interesting ‘Methot’ plankton tows to sample what is available for the fish to eat and give a more accurate and complete picture? How many adjectives can I use?

Before we dive too far into the depths, let me explain/refresh what plankton are. Plankton are any drifting organisms that inhabit the water columns of bodies of water. In fact, their name derives from the Greek for “wanderer,” and it would be helpful if you thought of them as drifters in the current…from deep in the ocean to up on the surface. They are generally broken down into plant-like-photosynthesizing plankton (phytoplankton) and animal-like plankton (zooplankton).
Phytoplankton are “photosynthesizing microscopic organisms that inhabit the upper sunlit layer of almost alloceans and bodies of water” (wikipedia). If you have taken biology or forensics with me, I have described some of them ad nauseam: diatoms? Those organisms that are in every body of water on the planet? Ah, yes. I can see it all coming back to you.

Zooplankton encompass a diverse range of macro and microscopic animals. They generally eat the phytoplankton or one another. Examples include krill, copepods, jellyfish, and amphipods.

In the great food web of life, other organisms eat the zooplankton. Among them was a pod of 50+ Humpback whales in the Barnabas Trough off of Kodiak Island. They were exciting enough that I went from being sound asleep to dressed and on the bridge in less than five minutes. Issue 12, Humpback Whales: Better than any alarm clock I have ever known delves into these organisms (Cartoon citations 1, 2, 3 and 4).


Our chief survey technician, Kathy Hough, took a lot of photos the following day as we traveled from Barnabas Trough to Alitak Bay. The three photos that follow and descriptions are courtesy of Kathy.

Adventures in a Blue World, Issue 12

Adventures in a Blue World, Issue 12

 

Whale tail: Individual humpback whales can be identified by the black/white pattern on the ventral side of the fluke (tail).  The pattern is like a human's fingerprint, unique to one animal.

Whale tail: Individual humpback whales can be identified by the black/white pattern on the ventral side of the fluke (tail). The pattern is like a human’s fingerprint, unique to one animal.

There is evidence of three whales in the photo above: the closest whale's rostrum (blow hole) is visible.  The second whale is diving and you can see the peduncle (the stocky part of the tail before the fluke).  The glassy area in the back of the photo is evidence of a recent dive and is called a "footprint."

There is evidence of three whales in the photo above: the closest whale’s rostrum (blow hole) is visible. The second whale is diving and you can see the peduncle (the stocky part of the tail before the fluke). The glassy area in the back of the photo is evidence of a recent dive and is called a “footprint.”

This Humpback was last seen in this area in 2004, and has not been seen since.  The white marks on its fluke are from a killer whale attack!  Kathy emailled photos of the whales to observers, and they were able to identify individuals!

This Humpback was last seen in this area in 2004, and has not been seen since. The white marks on its fluke are from a killer whale attack! Kathy emailled photos of the whales to observers, and they were able to identify individuals!

All hands on deck... 100+ Humpback Whales.  Darin and Staci.

All hands on deck… 100+ Humpback Whales. Darin and Staci.

Our team of scientists sample plankton using a Methot net, which is fine mesh and captures macroscopic organisms. We sample plankton for the same reason that we physically trawl for fish: we need to make certain what we are “hearing” is what is down there, with a focus on the types and sizes of the plankton. Additionally, knowledge about what and where plankton populations are will help with modeling the entire ecosystem. If you know where the food lives, its abundance and composition, by extension you have a much greater understanding of the predators, both pollock and whale.

(If you get a chance, check out this video about how whales hunt with bubble nets; fascinating!)

Personal Log

Bowditch

Bowditch

I try to spend time on the bridge every morning before breakfast. I bring up a cup of tea and watch the horizon lighten until the sun pushes its way up above the lingering clouds. This morning, I saw the green flash for the first time. The green flash is not a superhero. It is not a myth. It is not a sailor’s fish tail. It is real. Furthermore, if you still don’t believe me, the green flash is in the “bible” of maritime studies, The American Practical Navigator (Bowditch, if you are on a first name basis). I was told by Ensign David Rodziewiczthat “if it is in Bowditch, it must be true.” So there.

The green flash appears on the horizon just after the sun sets or just before it rises. For one moment on that spot the sky looks as if someone broke a green glow stick and smeared a distant florescent mark. As fast as it was there, it is gone. The name is appropriate: green flash. It occurs because light is bent slightly as it passes through the atmosphere (refraction); this bending is greatest on the horizon. Since light is made up of different colors with different wavelengths, the bending causes the colors to be seen separately. Bowditch says it is like offset color printing (nice metaphor, eh?). The red end of the spectrum is first to rise. The blue end of the spectrum is scattered the most by the atmosphere, leaving behind the momentary and memorable second of green.

Evidently, to see the green flash is considered very good luck. I already feel very lucky. I am in one of the most beautiful places in the world, on a ship with interesting and intelligent people, driving around the Gulf of Alaska learning about science and occasionally checking out whales. If I can get luckier than this… well… wow.

Tomorrow is the last day of our cruise, but I have a few more cartoons up my sleeves, so keep checking back. In the meantime, thank you to the incredible staff of the Oscar Dyson, the scientists of MACE, my rockin’ cohort Staci, and the NOAA Teacher at Sea program.

Until our next adventure,
Cat

p.s. Whales have the worst morning breath I have ever smelled. I know it isn’t really their fault–imagine having 270-400 baleen sheets on either side of your mouth that you could get krill stuck in…

Take it to the Bridge...

Take it to the Bridge…

Oscar Dyson, me mateys.

Oscar Dyson, me mateys.

Caitlin Thompson: Zooplankton, Ocean Currents, and Wave Gliders, August 7, 2011

NOAA Teacher at Sea
Caitlin Thompson
Aboard NOAA Ship Bell M. Shimada
August 1 — 14, 2011

Mission: Pacific Hake Survey
Geographical Area: Pacific Ocean off the Oregon and Washington Coasts
Date: August 7, 2011

Weather Data from the Bridge
Lat. 47 degrees, 00.8N
Long. 124 degrees, 29.8W
Present weather: Cldy 8/8
Visibility: 10 n.m.
Wind direction: 323
Wind speed: 08 kts
Sea wave height: 1 feet
Swell waves – direction: –
Swell waves – height: –
Sea water temperature: 13.7 degrees C
Sea level pressure: 1018.8 mb
Temperature – dry bulb: 15.8 degrees C
Temperature – wet bulb:  14.7 degrees C

Science and Technology Log

On the fish deck in my work clothes

On the fish deck in my work clothes

The Shimada conducts research around the clock, with crew members working twelve-hour shifts. So far, I have worked with the acoustics team studying hake during the day, when the hake school together and are easy to fish. Last night I branched out, staying up with Steve Pierce, the oceanographer studying ocean currents, Jennifer Fisher, a faculty assistant at Oregon State University (OSU) who is studying zooplankton, and her intern, Angie Johnson, a graduate student at OSU. All the different research on this trip complements each other, and I learned more about the acoustic team’s work from the night people.

Gray's Harbor Transects

Gray's Harbor Transects

The map at right shows the transects we follow and the stations that the night team takes samples, which Steve chooses. Just like the acoustics team, he only chooses sites on the east-west transects. The night team usually works one transect ahead of the day team, and must have the ship back where they started by sun-up. Steve is mapping small currents because, he says, surprisingly little is known about ocean currents, even though they have a tremendous impact on ocean life.

He is especially interested in the polar undercurrent that brings nutrient-rich water from the south up along the west coast. A small current, it is nonetheless important because of the nutrients it carries, which come to the surface through upwelling. He uses an acoustic device, the Acoustic Doppler Current Profile (ADCP), to find the velocity of the water at various depths. The data from the ADCP is skewed by many factors, especially the velocity of the ship. Later, Steve will use trigonometry to calculate the true velocity. He also uses the Conductivity, Temperature, Depth (CTD) meter, lowered into the water at every station during the night. The CTD gives much more information than its name would suggest, including salinity, density, and oxygen. It is deployed with a high-speed camera and holds bottles to capture water samples. I was impressed by the amount of work – and math! – that Steve does in between cruises. When he has down time on this cruise, he told me, he is calculating work from two years ago.

Jennifer divides a sample in the Folsom plankton splitter

Jennifer divides a sample in the Folsom plankton splitter

Jennifer and Angie are studying plankton, the organisms at the very bottom of the food web. Immediately, I recognized euphausiids, or krill, from the contents of hake stomachs. Actually I recognized their small black eyes, which always reminded me of poppy seeds when I saw them in hake stomachs. Jennifer is conducting this work through her group Northwest Fisheries Science Center, which, as she describes it, gives her a wonderful freedom to research different projects related to ocean conditions, especially salmon returns. In this project, they measuring phytoplankton, tiny, photosynthetic organisms, by measuring chlorophyll and nutrients. They are also looking at zooplankton, like euphausiids, salps, and crab larvae, which we examined other the microscope. To help the acoustics team refine their ability to use sonar to identify zooplankton, Jennifer and Angie record certain species. The acoustics team will match up the acoustics data that is continuously generated on this ship with the samples.

Angie

Angie takes water samples from the CTD.

Today, the second catch of the day was aborted because of whales too close to the ship. However, the NOAA’s Pacific Marine Environmental Laboratory (PMEL), had asked the Shimada to investigate its waveglider. A waveglider is type of robot called an autonomous underwater vehicle (AUV). Programmed to travel and record data, it does not need an operator. The PMEL folks were concerned, however, that its AUV might have a problem.The bridge set the course for the AUV, described as a yellow surfboard, and I headed up to the flying deck, the highest deck and an ideal spot for observation, to watch for it. Immediately we saw a humpback whale, just starboard of the ship, spout and roll through the water, its tail raised in the air. Soon the AUV appeared. We saw nothing wrong with it but communicated our observations, photographs, and video tape of it to PMEL. The PMEL’s system of wavegliders monitor carbon dioxide levels and use the kinetic energy of ocean waves to recharge the batteries. The acoustics team hopes to get their own waveglider next year to collect acoustic data in between transects. As I was peering  over the edge of the boat, examining the surfboard-like robot below, I heard a loud splash. A bout ten  Dall’s porpoises were playing around the bow of our boat, rippling in and out of the water. Dall’s porpoises are tremendously playful creatures, and will often play around ships. But our ship was barely moving, and the porpoises soon lost interest and swam away.

Wave Glider

Wave Glider, seen from above

Personal Log

I’m getting a little of everything on this cruise. I would have stayed up two nights ago for the deploymentof the CTD and zooplankton samples, but the propeller developed a loud enough whamming sound to suspend all operations indefinitely. I woke up at 4:00 AM yesterday because the boat was swaying back and forth violently. (Violently by my standards, that is; more experienced mariners insist the swell is nothing.) Since our bunks go port to starboard, I could feel my weight sliding from hip to head to hip to head as I was rocked back and forth in bed. Meanwhile a discarded lightbulb in a metal shelf was rolling back and forth steadily – rattle-rattle-WACK! rattle-rattle-WACK! – until Shelby Herber, a student at Western University and my roommate, got up, found the culprit, and wrapped it in a shirt. When I woke again, it was eleven hours after the discovery of the problem with the prop and well past breakfast, and I started to get up until Shelby told me we were off transect, headed to shore because of the propeller.

Wave Glider

Wave Glider from beneath the water, taken from PMEL's website

So we took our time getting up. But when I finally arrived in the acoustics lab, Rebecca was running up the hall, saying, “Caitlin, I was looking for you! There’s a great big shark outside, and we’re pulling up the ROV!” The ROV is the remotely controlled vehicle, a robot like the AUV, but one that requires an operator to make it move. Unfortunately, out on the fish deck, the ROV was being put away and the shark gone off on his fishy business. To console me, John had the videotaped footage from the ROV and the dorsal fin of the shark, and showed me both. The ROV revealed no damage and I was invited down to the winch room, where the bang-bang-bang coming from the propeller was unnerving.

ROV

Puzzled birds approach the ROV

Everyone was in an uproar trying to decide what to do, an uproar made all the more dramatic by the steady lurching and swaying of the ship, which throughout the day has sent most of the scientists to their room for at least a few hours and most of the deck hands to tell stories of unhappy tourists who couldn’t find their sea legs. Finally, the engine guys decided the warped propeller would not prevent us from getting to Port Angeles, and Rebecca decided it would not interfere with the acoustics, and we got back on transect.

ROV

ROV

I’m getting a little bit of everything on this cruise. I’ve seen sharks and marines mammals, calm seas and rockier seas, an impressively well-functioning ship and a number of technological problems. I’ve interviewed scientists, NOAA Corps officers who command the ship, and crew members who recount endless adventures at sea. I’m even signed up for the cribbage tournament, which I’m not entirely thrilled about since I don’t know how to play bridge. I’ve been impressed by how much time and information everyone seems to have for me. I am constantly thinking how I can bring this experience back to my students. Some ideas are to have a science and math career day, collect weather data like the data the bridge collects, dissect hake, and examine zooplankton under a microscope. Various people on board have volunteered to help with all my ideas.

Caitlin Thompson: Going Fishing! August 4, 2011

NOAA Teacher at Sea
Caitlin Thompson
Aboard NOAA Ship Bell M. Shimada
August 1 — 14, 2011

Mission: Pacific Hake Survey
Geographical Area: Pacific Ocean off the Oregon and Washington Coasts
Date: August 4, 2011

Weather Data from the Bridge
Lat. 46 degrees 22.4 N
Long. 124 degrees 41.1
Present weather: cloudy
Visibility: 10 n.m.
Wind direction: 330
Speed 11 kts
Sea wave height: 2-3 feet
Swell waves – direction: 310
Swell waves – height: 3-4 feet
Sea level pressure: 197.3 mb
Temperature – dry bulb: 17.0 degrees C
Temperature – wet bulb: 15.0 degrees C

Science and Technology Log

Shimada

Me in front of the Shimada.

Yesterday, I saw, sexed, and measured my first hake. And my second hake, and hundredth hake, and two hundredth hake. Most of the time, the scientists on the acoustics team watch computer monitors that show acoustic data as colors to represent life under the ship. Twice today, however, they identified large populations of hake and decided to fish for them in order to get more accurate data.

Pressure Housing

The pressure housing, held together by electrical tape and sponges, holds the battery and data storage for the light, lasers, and camera attached to the net.

Both times, the ship went into immediate action. Upstairs in the bridge, or command room, the NOAA officers slowed and repositioned the ship. Two scientists watched for marine mammals. If mammals were too close, we would have to abort the operation entirely. On the fish deck, John Pohl, on the acoustics team, taught me to assemble the pressure housing and attach it to the net. Objects attached to the net include the video camera, which will film anything passing by the mouth of the net, a four-beam laser to judge the length of the images that are filmed, a light to illuminate the water, batteries for power, and another camera for storing the data. The crew began lowering the net.

Hake

Josh Gunter, survey technician, operates a hatch to let hake onto the flow cale, which will find the mass of the whole haul.

For me, the real excitement began once the fish began pouring onto a conveyor belt into the fish lab. First, we sorted the fish by species. In the first haul, the fish were mostly hake, as intended, but we also caught three yellow-tail rockfish and three eulachons, a type of smelt. In the second haul, there was largely yellow-tail rockfish and hake, with several Pacific Ocean perch and widow rockfish. The rockfish were difficult to sort: they have dangerous spines and fight hard. Alicia Billings, a fisheries biologist on the acoustics team, taught me how to pick them up with one hand over their eyes and the other firmly grasping their tails. Even so, we both had a few close calls. We threw most of the fish right back into the ocean but kept about three hundred hake to sex and scale. With another fifty hake, we put then stomachs in individual bags so that the lab on shore can determine what the hake were eating. We also stored the otolith, or ear bones, in order to determine the age of the hake. Just like the rings of a tree, otoliths show growth rings every year.

Fish Lab

In the wet lab, the acoustics team prepares for the next batch of hake. From left Alicia Billings, Steven de Blois, and Dr. Rebecca Thomas

Finally, we cleaned up and settled back in the acoustics lab to watch for the next batch of fish.

The monitors use echosounders, which are exactly how they sound: Signals (sound waves) are emitted from beneath the ship and echo back once they hit something. The computer records the distance of an object by how long it takes for the signal to return.  For example, suppose a fish were right at the surface. The signal would hit it and return in very little time.

Echosounder

The monitor shows the depth of the ocean floor, sea surface, and objects in between.

On the other hand, in deep water the signal would take much longer to hit the bottom of the ocean and return. See the thick red line on the graph to the left? That’s the ocean floor. Notice how it curves down on the right at the edge of the continental shelf. The flat line at the top of the graph is the surface of the ocean. The scattered dots in between are most likely fish. The scientists can guess the kind of fish and the number of fish by the pattern and color of dots. All the color below the ocean floor is meaningless noise. Look to the upper left-hand corner of the graph to find the frequency of the signal, measured in kilohertz (KHz). The lower frequencies (20 kHz and 38 kHz) tend to measure larger objects and to go deeper in the water. These frequencies are perfect for finding hake. The higher frequencies (120 kHz and 200 kHz) measure smaller objects. For example, shortly before we started the first haul, we saw a large number of plankton, which showed up bright blue on the 120 kHz and 200 kHz frequencies but barely showed at all on the lower frequencies.

You can follow the progress of the Shimada at shiptracker. We’re headed for Port Angeles on August 14, making East-West transects along the way.

Larry

Chief Scientist Larry Hufnagle in the acoustics room

Personal Log

I am so happy to be at sea. The journey was delayed an entire day because of a problem with a valve, and we finally set sail yesterday. The skies are blue and the ocean calm, and I am constantly learning new stuff. I’ve had to learn to lift my feet when stepping through a doorway (I forgot once and went sprawling!) and to memorize the complicated series of halls and ladders to get from the fly deck to the bridge to the mess room to my stateroom. I’ve had to memorize thirty-some names.  The scientists have been incredibly patient, explaining each part of their work while I take copious notes. Working in the fish lab is my favorite part so far. It’s fascinating and satisfying work.

I am impressed by the sense of camaraderie on this ship. The scientists on the acoustics team – also known as the hake people –  keep up a constant, teasing banter, which only turns serious when discussing science. With science, they all have a different opinions. Before fishing today, Chief Scientist Larry Hufnagle worried that there were too few fish shown on the monitor. He said, “I don’t even know how you would fish on this stuff.” Dr. Rebecca Thomas, a research fishery biologist on the acoustics team, seemed to think there were plenty of fish, but suggested leaving the net in for a longer amount of time for a larger sample. After much more discussion, the team decided on a strategy and put in the net. I’m impressed how often they disagree and how carefully they listen to one another’s ideas.

Kathleen Harrison: Finding Fish, July 12, 2011

NOAA Teacher at Sea
Kathleen Harrison
Aboard NOAA Ship  Oscar Dyson
July 4 — 22, 2011

Location:  Gulf of Alaska
Mission:  Walleye Pollock Survey
Date: July 12, 2011

Weather Data from the Bridge
Air Temperature:  10.15° C, Sea Water Temperature:  7.6° C
True Wind Speed:  12.26 knots, True Wind Direction:  191.38°
Very foggy, visibility < 1/4 mile
Door open on bridge to hear other fog horns
Latitude:  56.07° N, Longitude:  158.08° W
Ship Heading:  24°, Ship Speed:  11.7 knots

Science and Technology Log:  Finding Fish

In a previous log, I talked about using nautical charts and trawling as 2 methods used in calculating the biomass of Walleye Pollock in the Gulf of Alaska.  Finding the fish to catch is tricky business in the ocean, they don’t usually come up to the surface and say hi.  The NOAA scientists working on the Walleye Pollock Survey spend a lot of time looking for fish, so that their trawling efforts won’t be wasted (that is the general idea, anyway).  How do you look for fish in the ocean?  With acoustics, of course, another method used in calculating biomass.

Acoustics is the use of sound, which will travel through the water, and bounce off of objects that it hits.  There is Simrad ER60 echosounder  that operates 5 transducers mounted on the center board under the ship, and it continuously sends out sound waves.

multibeam sonar mapping the ocean floor

The Simrad ER60 echosounder sends sound directly under the ship, finding fish anywhere in the water column.

In the Acoustics Lab of the Oscar Dyson, the data from the multi-beam echosounder is being studied all of the time.  The sound waves leave the device, travel down, hit the swim bladder in a fish (the fish doesn’t even know), and reflect back to the ship.  The time it takes for the sound to return is used to calculate the distance down, and a computer generated picture called an echogram is produced.

echogram shows surface, fish, and bottom

The echogram shows plankton at the surface in blue/green, fish near the bottom as red/brown spots, and the ocean floor as a red/brown line.

The echogram tells the scientists several things.  The surface of the water is shown, with surface dwelling organisms such as krill, phytoplankton, zooplankton, and juvenile fish.  The fish that are mid-water are shown as well, showing up as red or blue dashes or blobs.  This is where the Pollock usually are.  Some fish are bottom feeders, and the red and blue dashes on the bottom represent those.  The ocean floor is also shown, which is very important when choosing which type of trawl to use.   If the bottom is flat, the Poly Nor’Easter could be used to capture to fish on the bottom.  The Aleutian Wing Trawl might be used in mid water if the bottom is rocky and irregular.

Now, looking at the fish from the surface is nice, but wouldn’t it be better to see them close up?  Of course!  The scientists have another tool at their disposal, and no, it isn’t me diving down to the fish (brrr).  This tool is called a Drop Target Strength, or DTS.

echosounder can be dropped into water

The Drop Target Strength (DTS) can be lowered into the water, and get closer to the fish. The information is fed into the computer by a water proof cable.

About once a day, or every other day, the DTS is lowered over the side, and it starts sending out sound waves (3 pings/second), just like the echosounder mounted on the ship.  The advantage with the DTS, though, is that it is closer to the fish, giving a more detailed and accurate picture.  Individual fish can be sighted.  Taking a picture of a fish is kind of like taking a picture of a toddler, they don’t hold still very well.  So, a count of the fish on the echogram might not be exact.  Also, they might change the angle of their body, making the sound wave reflect off their swim bladder at a different angle.  The colors on the echogram are significant:  brown and red mean a strong signal, yellow is medium, and green and blue indicate a weak signal.

echogram shows individual fish

Studying the echogram from the DTS gives scientists a better picture of where the fish are. Each individual wavy line is probably a separate fish.

The scientists will study the echograms to determine where the fish are, and make a decision to fish or not.  Once fishing begins, they will move from the acoustics lab to the bridge, and study the echograms there.  An estimate of how many fish are in the net is made, and then the scientists will ask the crew to “haul back” the net.   (I am learning a whole new language!)  Then, things get very busy as we head to the fish lab to process the fish.

scientists at their desks in the acoustics lab

Here are the NOAA scientists that I am privileged to work with on the Oscar Dyson: (left to right) Darin Jones, Fish Biologist, Denise McKelvey, Fish Biologist, Neal Williamson, Chief Scientist.

New species seen:

Giant Pacific Octopus (juvenile, 1 cm)

Opalescent Squid

Chinook (King) Salmon

Egg yolk jelly fish

Sculpin (juvenile)

North Pacific sea nettle

Spud sponge

tiny squid, only 2 cm long

These are juvenile squid, about 2 cm long. They are nearly transparent.

giant pacific octopus, juvenile, only 1 cm

This is a juvenile Giant Pacific Octopus, only 1 cm wide, complete with 2 huge eyes, and 8 perfect legs.

Personal Log

My days have developed a routine now:  wake at 3:30 am (ugh), start my shift in the acoustics lab about 4:00, breakfast at 7:30, lunch at 11:30, end my shift at 4:00 pm, dinner at 5:30, shower, in bed by 8:00.

my window and life boats

See the orange life saving ring? My window is just to the right of the ring. The 3 white canisters on the back wall hold life rafts that inflate upon release of the canister.

In between these times, I work on my Teacher at Sea log, post pictures on Facebook, read and answer e-mail, visit the bridge and ask lots of questions, and of course, process fish whenever there is a trawl (very fun).  Today marks the halfway point of our cruise!  The ship is quieter than I thought, even though there are 35 people on board, the most that I ever see might be 10 during mealtimes.  There is constant background noise of the ship’s engines, waves hitting the bow of the ship, creaks and groans of the furniture as the ship rolls, but I am used to it now, and hardly notice it.  I am thankful for the calm weather that we have had so far.

Anne Mortimer: Fishing, July 7, 2011

NOAA Teacher at Sea
Anne Mortimer
Onboard NOAA Ship Oscar Dyson
July 4 — 22, 2011 

Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska
Date: July 7, 2011

Weather Data from the Bridge
Air temperature: 9.53 C, Foggy
Sea temperature: 8.19 C
Wind direction: 145
Wind Speed: 18.73 knots
Barometric pressure: 1013.22 mbar

Science and Technology Log

Last night, we attempted a bottom trawl for walleye pollock. The way scientists know that fish are present is by using acoustic sampling. The centerboard of the ship is set-up with sound emitting and recording devices. When a sound wave is emitted toward the bottom, it will eventually be returned when it hits a fish or the ocean bottom. This is called echo-sounding and has been used by sport & commercial fisherman and researchers for many decades. The sound waves are sent down in pulses every 1.35 seconds and each returned wave is recorded. Each data point shows up in one pixel of color that is dependent on the density of the object hit. So a tightly packed group of fish will show as a red or red & yellow blob on the screen. When scientists see this, they fish!

This echogram shows scientists where fish can be found.

The scientists use this acoustic technology to identify when to put the net in the water, so they can collect data from the fish that are caught. The researchers that I am working with are specifically looking at pollock, a mid-water fish. The entire catch will be weighed, and then each species will be weighed separately. The pollock will all be individually weighed, measured, sexed, and the otolith removed to determine the age of the fish. Similar to the rings on a tree, the otolith can show the age of a fish, as well as the species.

pollock otolith

A pollock otolith.

Pollock otolith in my hand

These scientists aren’t the only ones that rely on technology, the ships navigation systems is computerized and always monitored by the ship’s crew. For scientific survey’s like these, there are designated routes the ship must follow called transects.

globe chart

This chart shows the transects, or route, that the ship will follow.

This chart shows the route (white line) of the ship once fish were spotted. When scientists find a spot that they want to fish (green fish symbol), they call up to the bridge and the ship returns to that area. As the ship is returning, the deckhands are preparing the net and gear for a trawl.

Personal Log

I think that I must have good sea legs. So far, I haven’t felt sick at all, although it is very challenging to walk straight most times! I’ve enjoyed talking with lots of different folks working on the ship, of all ages and from all different places. Without all of the crew on board, the scientists couldn’t do their research. I’ve been working the night shift and although we’ve completed a bottom trawl and Methot trawl, we haven’t had a lot of fish to sort through. My biggest challenge is staying awake until 3 or 4 am!

Did you know?

That nautical charts show depths in fathoms.  A fathom is a unit of measurement that originated from the distance from tip to tip of a man’s outstretched arms. A fathom is 2 yards, or 6 feet.

Species list for today:

Humpback Whale

Northern Fulmar

Tufted Puffin

Stormy Petrel

petrel

Fish biologist Kresimir found this petrel in the fish lab; attracted to the lights it flew inside by accident. The petrel is in the group of birds called the tube-nosed sea birds. They have one or two "tubes" on their beak that helps them excrete the excess salt in their bodies that they accumulate from a life spent at sea.

In the Methot net:

Multiple crab species including tanner crabs

Multiple sea star species, including rose star

Sanddollars

Juvenile fish

Brittle stars

Sponge

Multiple shrimp species including candy striped shrimp

shrimp variety

These are some of the shrimp types that we found in our Methot net tow.

Becky Moylan: Acoustics and Trawling, July 5, 2011

NOAA Teacher at Sea
Becky Moylan
Onboard NOAA Ship Oscar Elton Sette
July 1 — 14, 2011


Mission: IEA (Integrated Ecosystem Assessment)
Geographical Area: Kona Region of Hawaii
Captain: Kurt Dreflak
Science Director: Samuel G. Pooley, Ph.D.
Chief Scientist: Evan A. Howell
Date: July 5, 2011

Ship Data

Latitude 1940.29N
Longitude 15602.84W
Speed 5 knots
Course 228.2
Wind Speed 9.5 knots
Wind Dir. 180.30
Surf. Water Temp. 25.5C
Surf. Water Sal. 34.85
Air Temperature 24.8 C
Relative Humidity 76.00 %
Barometric Pres. 1013.73 mb
 Water Depth 791.50 Meters

July 5, 2011

Science and Technology Log

Work is going on 24 hours here on the ship. The crew have different shifts, so nothing ever stops. It may be 3:00 in the morning, and you’ll see people sorting fish, filtering water, or working the acoustics table.


Acoustics Computer Screen

Acoustics Computer Screen

To improve the accuracy of identifying what organisms are seen on the acoustic system, Sette researchers collect samples from the scattering layers at night using a large trawl net towed from the ship.One important part of the research here is using the acoustic system to find where groups of fish and other organisms are located. This is done with a “ping”, or noise, sent down in the ocean. The sound waves bounce back when they find something, letting scientists know where, and sometimes what, is swimming underneath. Computers keep data on all the different sound waves showing patterns of fish movement. They have found that some groups move upward during the nighttime, and then move back down during the day.

Cookie Cutter Shark

Cookie Cutter Shark

Trawl Net

Trawl Net

Every night on the ship, there is at least one trawl. The method of trawling started back in the 1400′s. Some people use these nets to catch large amounts of fish to sell, and that has been an environmental concern. NOAA is using this method as a scientific sampling, or survey, method to try and help the environment. They are trawling in the Epipalagic Zone (mid to shallow) which is around 200 meters deep, depending on the total depth at location and where the acoustics pick up signals.

Scientists want to find out the status of the smaller life in order to try and predict the outcome of the larger life. Only a small amount is caught for sampling. They weigh, sort, count, and study them. The goal is to be aware of what is happening in this area of the ocean. Some of the species they have found are different types of shrimp, squid, Myctopids, small crabs, and jellies. Last night they wound up with two Cookie Cutter Sharks. These results will then be combined with the measured acoustic data in order to improve the accuracy and effectiveness of acoustic monitoring.

Examining a Trawl Catch

Examining a Trawl Catch

Puffer Fish

Puffer Fish

One scientist from New York, Johnathan, is looking for specific species of Myctopids. He studies them under the microscope and records detailed data found. The Myctopids are sometimes called Lantern Fish. This is because they have organs that produce light. The lights are thought to be a way of communicating with other fish and also as a camouflage. As mentioned earlier, some fish rise to shallower waters at night and the Myctopid is one of these. The reason might be to avoid predators, yet also to follow zooplankton which they feed upon.


Personal Log

Abandon Ship Suits

Abandon Ship Suits

Last night some of us went out on deck to watch the Kona fireworks. I didn’t realize how far out we were until I saw how tiny the little ball of colors appeared. You could see three different areas along the coast where they were shooting off fireworks. As a fourth of July treat, the cooks barbecued on deck and made special deserts. I especially liked the sweet potato pie.

This morning I was out at 6am preparing the CTD for deployment. It is getting easier each time. There are many precautions and steps to make sure the procedure is done correctly and safely. We could only drop it to 200 meters today because this area is shallower here. I watched and learned how to control the computer from the inside. Very impressive!

CTD Screens

CTD Screens

I’m wondering when the ship is going to have another “abandon ship drill”. That’s when we all carry our floatation suits to the upstairs deck and put them on, and it is not easy to do. You lay the suit down, sit on it, and put your legs in first. Then you stand up, pull the suit hood on, then lastly the arms. This is because the hands don’t have fingers. It is quite a funny sight.

I found out today that the 3am trawl ended up with only one fish because a Cookie Cutter Shark had eaten a round hole in the net. This is where they get their name. They always bite a round hole. Some have even eaten a hole out of humans!

Jason Moeller: June 25-27, 2011

NOAA TEACHER AT SEA
JASON MOELLER
ONBOARD NOAA SHIP OSCAR DYSON
JUNE 11 – JUNE 30, 2011

NOAA Teacher at Sea: Jason Moeller
Ship: Oscar Dyson
Mission: Walleye Pollock Survey
Geographic Location: Gulf of Alaska
Dates: June 25-27, 2011

Ship Data
Latitude: 55.58 N
Longitude: -159.16 W
Wind: 14.11
Surface Water Temperature: 7.2 degrees C
Air Temperature: 9.0 degrees C
Relative Humidity: 90%
Depth: 85.61

Personal Log
Anyone who has seen the show Deadliest Catchknows how dangerous crab fishing can be. Fishing for pollock, however, also has its dangers. Unfortunately, we found out the hard way. One of our deck hands caught his hand between a cable and the roller used to pull up the trawl net and hurt himself badly.

Cable

The cable and the roller.

Fortunately, the injuries are not life threatening and he will be fine. The injuries did require a hospital visit, and so we stopped at Sand Point to treat him.

Town

This is the town of Sand Point.

airstrip

Clouds hang over the hills at Sand Point. The airstrip is in the left edge of the photo.

We stayed at Sand Point for nearly 48 hours. What did we do? We fished, of course! We used long lines and hooks, and had a great time!

lines

Bill and Alex cast fishing lines in the harbor. We tied the lines off on the boat and hauled them up from time to time to check the bait.

Alex

Alex with a flounder that he caught! He also caught several cod and a 32-lb Pacific halibut!

cod

Cod and the flounder in a bucket!

Tammy

As with every fishing trip, we also managed to catch things that we didn't mean too! Tammy (the other NOAA Teacher at Sea) especially liked the kelp!

urchin

A few visitors always hitched a ride on the kelp we caught. Here is a tiny sea urchin.

crab

This crab was another hitchhiker on the kelp.

starfish

We were bottom fishing for Halibut, and a starfish, the largest one I've ever seen, went after the bait!

A one-day fishing license in Alaska costs $20.00. We had internet, so five of us went online and bought the fishing passes. Was it worth it?

Halibut

You bet it was! This is the 25-lb halibut I caught! It was AWESOME!!!

We filleted it and had the cooks make it for dinner. With the halibut, we also cut out the fleshy “cheeks” and ate them as sushi right on the spot! It doesn’t get any fresher (or tastier!) than that!

Science and Technology Log
Today we will look at the acoustic system of the Oscar Dyson! Acoustics is the science that studies how waves (including vibrations & sound waves) move through solids, liquids, and gases. The Oscar Dyson uses its acoustic system to find the pollock that we process.

The process begins when a piece of equipment called a transducer converts an electrical pulse into a sound wave. The transducers are located on the underside of the ship (in the water). The sound travels away from the vessel at roughly 1500 feet per minute, and continues to do so until the sound wave hits another object such as a bubble, plankton, a fish, or the bottom. When the sound wave hits an object, it reflects the sound wave, sending the sound wave back to the Oscar Dyson as an echo. Equipment onboard listens to the echo.

The computers look at two critical pieces of information from the returning sound wave. First, it measures the time that it took the echo to travel back to the ship. This piece of information gives the scientists onboard the distance the sound wave traveled. Remember that sound travels at roughly 1500 feet per minute. If the sound came back in one minute, then the object that the sound wave hit is 750 feet away (the sound traveled 750 feet to the object, hit the object, and then traveled 750 feet back to the boat).

The second critical piece of information is the intensity of the echo. The intensity of the echo tells the scientists how small or how large an object is, and this gives us an idea of what the sound wave hit. Tiny echos near the surface are almost certainly plankton, but larger objects in the midwater might be a school of fish.

good fishing

An image of the computer screen that shows a great number of fish. This was taken underneath the boat as we were line fishing in Sand Point.

poor fishing

The same spot as above, but with practically no fish.

fishing

An image of the screen during a trawl. You can actually see the net--it is the two brown lines that are running from left to right towards the top of the screen.

One of the things that surprised me the most was that fish and bubbles often look similar enough under water that it can fool the acoustics team into thinking that the bubbles are actually fish. This is because many species of fish have gas pockets inside of them, and so the readout looks very similar. The gas pockets are technically called “swim bladders” and they are used to help the fish control buoyancy in the water.

swimbladder

Swim bladder of a fish.

Species Seen
Northern Fulmar
Gulls
Cod
Pacific Halibut
Flounder
Sea Urchin
Crab
Kelp

Reader Question(s) of the Day
Today’s questions come from Kevin Hils, the Director of Chehaw Wild Animal Park in Chehaw, Georgia!

Q. Where does the ship name come from?
A. Oscar Dyson was an Alaska fisheries industry leader from Kodiak, Alaska. He is best known for pioneering research and development of Alaska’s groundfish, shrimp, and crab industry. Dyson was a founding partner of All Alaskan Seafoods, which was the first company actually controlled by the fishermen who owned the vessel. He also served on the North Pacific Fisheries Management council for nine years. He is in the United Fishermen of Alaska’s hall of fame for his work. The ship was christened by his wife, Mrs. Peggy Dyson-Malson, and launched on October 17, 2003.

Dyson

Oscar Dyson

launch

The launching of the Oscar Dyson

Q. How do you see this helping you teach at Knoxville Zoo, not an aquarium?
A. This will be a long answer. This experience will improve environmental education at the zoo in a variety of different ways.

First, this will better allow me to teach the Oceanography portion of my homeschool class that comes to the zoo every Tuesday. For example, I am in the process of creating a hands on fishing trip that will teach students about the research I have done aboard the Oscar Dyson and why that research is important. Homeschool students will not just benefit from this experience in Oceanography, but also in physics (when we look at sound and sonar) and other subjects as well from the technical aspects that I have learned during the course of the trip.

Scouts are another group that will greatly benefit from this experience as well. The Girl Scout council wishes to see a greater emphasis in the future on having the girls do science and getting real world experiences. While the girls are still going to desire the animal knowledge that the zoo can bring, they will also expect to do the science as well as learn about it. My experience aboard the Dyson will allow me to create workshops that can mimic a real world animal research experience, as I can now explain and show how research is done in the field.

The same can be said of the boy scouts.

In addition, one of the most common badges that is taught to boy scout groups that come in is the fish and wildlife merit badge. In the past, the badge has primarily focused on the wildlife aspect of this topic. However, I now have the knowledge to write and teach a fisheries portion for that merit badge, as opposed to quickly covering it and moving on. This will enrich future scouts who visit the zoo for this program.

A major focus for all scouts is the concept of Leave No Trace, where scouts are supposed to leave an area the way they found it. The fisheries research being done aboard the Dyson is focused toward that same goal in the ocean, where we are attempting to keep the pollock population as we found it, creating a sustainable fishery. The goal aboard the Dyson is similar to the goal in scouting. We need to be sustainable, we need to be environmentally friendly, and we need to leave no trace behind.

School children on field trips will greatly benefit, especially students in the adaptations section. There are some bizarre adaptations that I never knew about! For example, sleeper sharks slow, deliberate movement coupled with their fin and body shape basically make them the stealth fighter of the fish world. They can catch fish twice as fast as they are! Lumpsuckers are neat critters too! This knowledge will enhance their experience at the zoo during field trip programs.

Finally, I can pass the knowledge from this experience on to my coworkers. This will not only better the experience of my students, but it will also improve the outreach programs, the bedtime programs, the camps, and other programming done at the zoo.

Q. Are you old enough to be on a ship? You look like you’re 13???!!!!
A. SHHHHHHH!!!! You weren’t supposed to tell them my real age! They think I’m 24!

Fisheries Acoustics

NOAA Teacher at Sea: Tammy Orilio
NOAA Ship Oscar Dyson
Mission: Pollock SurveyGeographical
Area of Cruise: Gulf of Alaska
Date: 28 June 2011


Weather Data from the Bridge:
Latitude: 57.11 N
Longitude:  -155.58 W
Wind Speed:  3.61 knots
Surface Water Temp:  9.0 degrees C
Water Depth:  271.10 m
Air Temp:  8.3 degrees C
Relative Humidity: 84%

Science & Technology Log
Today we will look at the acoustic system of the NOAA Ship Oscar Dyson! Acoustics is the science that studies how waves (including vibrations & sound waves)  move through solids, liquids, and gases.  The Oscar Dyson uses an acoustic system to find the pollock that we process.

The process begins when a piece of equipment called a transducer converts an electrical pulse into a sound wave.  The transducers are located on the underside of the ship (in the water).   The sound travels away from the vessel at roughly1500 feet per minute, and continues to do so until the sound wave hits another object such as a bubble, plankton, a fish, or the bottom. When the sound wave hits an object, it reflects the sound wave, sending the sound wave back to the Oscar Dyson as an echo. Equipment onboard listens to the echo.

good fishing

An image of the computer screen that shows a great number of fish. This was taken underneath the boat as we were line fishing in Sand Point.

The computers look at two critical pieces of information from the returning sound wave. First,  it measures the time that it took the echo to travel back to the ship. This piece of information gives the scientists onboard the distance the sound wave traveled. Remember that sound travels at roughly 1500 feet per minute. If the sound came back in one minute, then the object that the sound wave hit is 750 feet away (the sound traveled 750 feet to the object, hit the object, and then traveled 750 feet back to the boat).
The second critical piece of information is the intensity of the echo. The intensity of the echo tells the scientists how small or how large an object is, and this gives us an idea of what the sound wave hit. Tiny echos near the surface are almost certainly plankton, but larger objects in the midwater might be a school of fish.

poor fishing

The same spot as above, but with practically no fish.

One of the things that surprised me the most was that fish and bubbles often look similar enough under water that it can fool the acoustics team into thinking that the bubbles are actually fish. This is because many species of fish have gas pockets inside of them, and so the readout looks very similar.  The gas pockets are technically called “swim bladders” and they are used to help the fish control buoyancy in the water.

Personal Log:

Well, it’s now Tuesday morning, and we are making excellent time on our way back to Kodiak.  The water has not been as rough as expected, thank goodness!  Yesterday’s forecast said we’d encounter winds up to 35 knots and seas up to 18 feet, but I have definitely not felt anything like that.  It’s not quite over yet, though, so I’m not getting my hopes up too much.

We’re scheduled to arrive in Kodiak sometime tomorrow (I don’t know the approximate time yet), or maybe even later tonight, which means I’ll have a day to kill there.  I’m looking forward to it because I didn’t get a chance to explore when I first arrived.  When I made it to Kodiak, I only had the clothes on my back, and it was raining for nearly the entire two days I was there, so I didn’t want to go outside and explore because if my clothes got wet, I had nothing else to change into!  One animal I haven’t seen on this trip is an eagle, and I hear they’re very easy to spot in Kodiak, so hopefully I’ll get a chance to look around tomorrow!

Question of the Day:

  • What is one way that bony fishes can control the amount of gas in their swim bladder?

No Fishing Today

NOAA Teacher at Sea: Tammy Orilio
NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 25 June 2011

Weather Data from the Bridge:
Latitude: 54.91
Longitude: -161.27
Wind Speed: 13.80 knots
Surface Water Temp: 7.9 degrees C

Water Depth: 113.78 m
Air Temp: 8.3 degrees C
Relative Humidity: 97%

Personal Log:
Unfortunately, it’s been another day of no fishing for me :( My shift just ended, and we’ve only seen small, scattered groups of fish on the acoustic displays today- not enough to put the nets into the water. Yesterday was nearly the same as today, but we did do a plankton trawl to sample the krill in the water. I’ll write more about that in another post.

From what I’ve heard from other Teachers at Sea, I expected to be working in the fish lab pretty much the entire duration of my 12 hour shift. Unfortunately, this hasn’t been the case! But, there’s not much I can do if there are only a scattering of fish in an area. Even the scientists are saying that they’re surprised by the lack of fish on this leg of the survey. I still have another 5 days or so (depending on when we start heading back to port, and if we’re working on the way there, or just straight sailing), so hopefully I’ll see some more action over the last few days of the trip. However, I know that we can’t control whether the fish are here or not- it’s all part of the science process!

The science team will be disembarking on Thursday June 30 and heading home, but the trip is definitely not over for the rest of the crew and NOAA officers. Another group of scientists and two more Teachers at Sea will be boarding the ship, and then they’ll set sail for another 3 weeks, doing the same thing we’ve been doing, just in a different part of the Gulf of Alaska. Then, the original group of scientists (that are on board now) and two more teachers will come back for the last leg of the trip. This method of switching people every few weeks is advantageous so that no one gets too run down or antsy to get off the ship. However, most of the deck crew, engineers, and NOAA officers stay onboard for all 3 legs of the trip- I don’t know if I could do that! I’ve been on board for 2 weeks now, and I’m doing fine, but I couldn’t imagine being on here for 9 or 10 weeks!

Lastly, here are a few photos of the area we’ve been in the last two days. Looking at our digital map, we’ve got nothing to look at but open water for the next 10 hours or so, but we’re moving into an area filled with lots of little islands in the next day, so I’m sure I’ll get some photos!

I can see Russia from my house!! (kidding, of course)

I can see Russia from my house!! (kidding, of course)

Margaret Stephens, May 19, 2011

NOAA Teacher at Sea: Margaret Stephens
NOAA Ship: Pisces
Mission: Fisheries, bathymetric data collection for habitat mapping
Geographical Area of Cruise: SE United States continental shelf waters from Cape Hatteras, NC to St. Lucie Inlet, FL
Dates of log: Thursday, 19 May through Saturday, 21 May, 2011

Here I am with the CTD equipment

Here I am with the CTD equipment

Weather Data from the Bridge
Position: Latitude 27.87, Longitude -80.16
Wind Speed 11.06 kts
Wind Direction. 131.46 º
Surface Water Temperature 26.88 ºC
Surface Water Temperature
Air Temperature 27.10 ºC
Relative Humidity 78.00 %
Barometric Pressure 1015.50 mb
Water Depth 28.05 m
Sky conditions: clear

Science and Technology Log

General Description of the Scientific Work Aboard Pisces
While at sea, the ship’s operations and scientific crews work in shifts 24/7 – yes, that’s twenty-four hours, every day, with ship operations, maintenance, data collection and gear deployment continuing day and night.
The scientific team, headed by Chief Scientist, Dr. Nate Bacheler, includes researchers who are mostly marine biologists specializing in fisheries. Each team member has complementary specialized skills such as acoustics (use of sonar for sea floor mapping), physical or chemical oceanography, underwater video camera operations, data management and analysis, and many aspects of fish biology.

The main mission of this research cruise is to study red snapper and related grouper species, fish that are of great importance economically and to the marine ecosystem in near shore areas off the southeastern coast of the United States. In particular, the team is studying where the fish are likely to be found (their spatial distribution patterns) and their numbers, or abundance, and population dynamics (how the populations change over time).

This work expands the knowledge needed to guide decisions about how to protect and manage fisheries in a sustainable manner. Healthy, sustainable fish populations are essential to the economy, to the function of healthy ecosystems, and as high-protein (and tasty) food sources. In the past, many fish species have been overfished, resulting in dangerous declines in their populations.
The scientific work on board Pisces for this project is divided into three main areas. This log entry gives an overview of each of the three main areas of work, with a more detailed account of the acoustics, or mapping portion. Upcoming logs will describe the other phases in more detail.

  1. Acoustics – Using the science of sound with advanced sonar and computer technology, the acoustics team maps the sea floor and identifies areas likely to be good fish habitat.
  2. Fish survey – The survey team sets baited traps to catch fish, then collects them, identifies the species, and records essential data about the species of most interest.
  3. Underwater videography – The video team attaches cameras to the traps to view the kinds and activities of fish in the water and assess the type of sea bottom, such as sandy or hard, flat or “bumpy”, regular or irregular.
  4. After all this information is collected in the field, much of the painstaking, detailed analysis takes place back in the home labs and offices of the researchers.

Acoustics Work
Since acoustics is the first step used to identify specific sites to set traps for the fish survey, we’ll start here.
Throughout a long night shift, from 6 p.m. until the work is complete, often 7 a.m. or later the following day, the acoustics team uses sonar (SOund NAvigation and Ranging) and computer analysis to map the sea floor and identify promising areas to set traps for the fish survey. See a detailed description of the sonar equipment and procedures below.

Investigator Jennifer Weaver showing GIS model of sea floor contours

Investigator Jennifer Weaver showing GIS model of sea floor contours

At 5 a.m., the acoustics team meets with Chief Scientist Nate to report any sites they identified overnight and select the stations to sample with fish traps and underwater cameras during the day. The team then converts their data into a kind of route map that the helmsman (the ship’s “driver”) uses to steer the ship along the designated survey route.

The acoustics team members possess extensive knowledge about fish habitats, geography and geology of the sea floor, and computer and sonar technology. They also need to be aware of the interactions among wind, weather and currents and understand charts (marine maps) and ship’s navigation. They constantly communicate with the ship’s bridge via the internal radio network.

Fish survey team prepares baited traps at dawn

Fish survey team prepares baited traps at dawn

The acoustics lab houses work space large enough for five to ten people, banks of computer screens, servers, and large-scale display monitors projecting images from the sonar devices, real time navigation, and views from cameras positioned in work areas on deck.

Once the now-very-sleepy acoustics lab team wraps up its nocturnal work, the team members turn in for a day’s (or night’s?) sleep, just as the other teams’ daylight tasks begin in earnest.

Fish Survey Work
By 6 a.m., in the predawn darkness, the rear deck becomes a hub of concentrated activity, with sounds muffled by the early ocean haze and drone of the engines and generators. The four or more members of the fish survey team, still rubbing sleep from their eyes, assemble on the stern deck (rear of ship or fantail) to prepare the traps to catch fish for the day. Before the sun rises, floodlights illuminate the work of cutting and hanging menhaden, whole fish bait, in the traps, securing the underwater cameras in place, tagging each piece of equipment carefully and checking that everything is ready for deployment.

Chief Scientist Nate Bacheler directs trap deployment from the dry lab

Chief Scientist Nate Bacheler directs trap deployment from the dry lab

Chief Scientist Nate directs the deployment of the traps from the dry lab, where he faces a bank of computer screens displaying maps of the identified sampling route, the ship’s course in real time, and camera shots showing the personnel and operations on deck. By radio, Nate directs the deck crew to lower the traps at each of the designated sites.

The ship is steered along the sampling route, dropping traps in each of six locations. Each trap is left in place for approximately ninety (90) minutes. Once the last trap is lowered, the ship returns to the first location and raises the traps, usually following the same order. The deck crew members, together with the fish survey team, empty any catch and ready the traps for redeployment.
Chief Scientist Nate Bacheler directs trap deployment from the dry lab

Then the fish survey team, coordinated by Investigator Dave Berrane, sets to work sorting, weighing and measuring any catch and immediately releasing any fish not needed for further study.

Investigator Christina Schobernd views underwater video with Chief Scientist Nate Bacheler

Investigator Christina Schobernd views underwater video with Chief Scientist Nate Bacheler

Videography Work
As soon as the traps are hauled aboard by the deck crew, the wet lab team detaches and dries the cameras and hands them to the dry lab, where the videography team, headed by Investigator Christina Schobernd, removes the memory cards and transfers and makes duplicates of the video files on computer drives. All the teams take extreme care to label, catalog and back up everything carefully. Data management and redundancy are essential in this business. The scientists view some of the footage immediately to see if the cameras are working properly and to make any adjustments necessary. They also look for anything unusual or unexpected, any fish captured on camera other than those that made it into the trap, and they assess how closely the sea floor type matched what was expected from the acoustic team’s mapping work.

Christina works well into the night to back up and catalog all the day’s video recordings.

Detailed Description of Fisheries Acoustics Surveys

Multibeam sonar mapping the seafloor. Image courtesy of Jill Heinerth, Bermuda: Search for Deep Water Caves 2009.

Multibeam sonar mapping the seafloor. Image courtesy of Jill Heinerth, Bermuda: Search for Deep Water Caves 2009.

Fisheries Acoustic Surveys: Acoustic surveys help determine the relative abundance of target species and provide information to determine catch rates and guidance for fisheries management.

The equipment aboard Pisces includes two types of sonar devices that use sound waves to measure the water depth, shape or contours of the sea floor, and to a limited extent, fish groupings, or aggregations. Sonar operates using established knowledge about how fast sound travels in water under different conditions to develop a three-dimensional image of the shape of the sea floor. The first type is known as split-beam sonar, which uses sound waves at different frequencies to provide a picture of the underwater environment. Pisces has a Simrad EK60 echosounder.

The second, more sophisticated and expensive system involves Multibeam sonar mapping. Aboard Pisces is a Simrad ME70 device. Multibeam devices emit sound beams that forms an inverted cone, covering a larger area and providing a more complete picture of the sea floor than the series of vertical or horizontal sound signals that the split beam sonar provides. As described above, the bathymetric mapping surveys are conducted primarily during the night, from sundown until dawn, when fish sampling and other ship operations are not taking place. Ideally, this allows the science team to map out a route of sampling sites for the next day’s fish trapping work. At the end of the overnight shift, the acoustics team presents its findings to the Chief Scientist, who then coordinates the day’s activities with the fish team, the ship’s bridge, and the deck crew headed by the chief boatswain.

It’s called “multibeam” because unlike the first single-beam sonars, which sent out one signal or ping, multibeam sonar sends out a whole group of pings at once. Multibeam sonar can cover a larger area than a single beam can. Here’s a Quicktime movie of multibeam sonar: http://oceanservice.noaa.gov/education/seafloor-mapping/movies/multi_240.mov

Personal Log

I cannot say enough about how friendly and helpful everyone on board has been to this neophyte. It takes a while to adjust to any new environment, but being on a ship at sea has its own learning curve. Pisces, at 209 feet long, operates like a small town. Because it is out at sea for weeks at a time, all supplies and systems must be operating 24/7 to keep the ship and crew focused on the appointed mission and keep everyone on board safe, comfortable, and able to do their jobs.

I spent the first two days getting acclimated to the layout of the ship, safety practices, meeting the members of the scientific crew, adjusting to the rigorous schedule, and doing my best not to commit any grave offenses or make big mistakes that would make the work of this very patient group of dedicated professionals any more difficult than it is already.

Sleep Time Because the ship’s work continues round the clock, sleep time varies, depending on the person’s position and duties. It is important for everyone aboard to be mindful that at any hour of the day or night, it’s likely that someone is sleeping. The mapping crew began a 6 p.m. to 6 a.m. shift (or later, until the work is finished) on our second day at sea, and most of them will keep that difficult schedule for the entire cruise. Since I’m the lucky one to experience every aspect of the work, I’ll rotate through the various jobs and schedules. For the first few days, I’ll work with the fish survey team, from 6 a.m. until their work is completed, which may mean a break for supper at 5 p.m. followed by a few more hours of lab work to process all the day’s catch. My first day on the acoustics team, I’m scheduled to start at 4 a.m. assisting their nightly wrap up, as by the last few hours of their shift, they are quite tired.

Dining and Comforts Aboard Ship

Chief Steward/Chef Jesse Stiggens with a Pisces creation, a vegetable quiche.

Chief Steward/Chef Jesse Stiggens with a Pisces creation, a vegetable quiche.

Chief Steward Jesse Stiggens and Assistant Steward Michael Sapien create a terrific, appetizing menu for the three main meals and plenty of extras and snacks available at any hour.

The stewards are very accommodating, so anyone who will miss a main meal because of their work or sleep schedule can sign up in advance for the stewards to set aside a full plate of delicious food for them. The mess (dining room on a ship) is open all day and night, with coffee, cold beverages, an array of sandwich fixings, cereals and assorted leftovers kept chilled for anyone to microwave anytime they get a hankering for a nibble or a bigger bite. And…very important for morale … there’s a freezer stocked with ice cream, even Blue Bunny (a favorite in the South that I had not seen before) and Häagen-Dazs. There’s also a big screen television in the mess. The lounge area has computers, a conference or game table, a small library of books, a large screen television and several hundred movie titles, even new releases, for the crew to enjoy in their off time. Also available are wonderful reclining chairs, so comfortable, I wish I had time to use them. The one and only time I tried one out, the fire alarm went off for our first drill, and I haven’t had a free moment since.

Doomsday Came and Went: Saturday, 21 May, 2001….and Pisces work continues
CNN reports: After months of warnings and fear, the Day of Rapture, as predicted by apocalyptic Christian broadcaster Harold Camping, passed without apparent calamity. Judgment Day was to have started at 6 p.m., but as darkness fell on many parts of the world, it appeared that heaven could wait. At this writing, there have been no reports of people soaring upward to the skies, but plenty of folks are talking about it.

That includes those of us on Pisces. The possibility that Doomsday was approaching generated some good-natured kidding and gallows humor. We had some debate about when the end would begin. Since most of the ship’s instruments use Greenwich Mean Time (GMT) as a reference, we speculated that our end time might occur four hours later than east coast Daylight Savings Time (DST).

Everyone had their eyes on the clock and the horizon as first, the predicted doomsday hour of 6 p.m. DST came and went, and then, four hours later, 6 p.m. GMT passed without incident. Any apprehensions were put to rest, and now we have new fodder for discussion.

Special Challenges for Research at Sea
Many people have the idea that science is neat, pretty and conducted in sterile lab environments by other-worldly thinkers in clean white lab coats. That is decidedly not the case in fisheries work at sea. This section lists the special challenges (or, as, some optimists would say, “opportunities”) of conducting shipboard research. Each log will focus on or give examples of one or more challenges.

  • Limits of “shooting in the dark” – Imagine a vast, dark, deep, ever-changing, difficult-to-penetrate area, with living organisms moving about in and out, with all kinds of surface, bottom, and in-between conditions. That’s what underwater research involves. Examples: The mapping team thinks it has found great habitat for red snapper and grouper, so the survey team expects a bountiful trap. But up comes nothing but a trap still full of untouched bait. Or, the habitat conditions look promising, but the current is too strong to set the traps safely.
  • The Unexpected – It is often said that the only thing predictable in field research of this kind is unpredictability! You just never know….
  • Curiosity-seekers and just plain business – recreational and commercial boats – Not surprisingly, the areas of interest for NOAA fisheries research are often favorite fishing grounds for recreational fishermen, scuba divers, and active routes for commercial ships. Therefore, Pisces crew and helm (the person steering the ship) must always be on alert for other boat traffic. Example: On Saturday, a small recreational boat occupied by partiers pulled up nearly alongside Pisces. Despite polite cautions and requests from our bridge for the small boat to move away to a safer distance, the visitors just kept waving and cheering for a while.

Challenges to come in next logs:

  • Changing sea conditions, weather, waves and current
  • Fatigue
  • Limited daylight hours
  • Emergencies
  • More unpredictables

Links & Resources

Donna Knutson, September 24, 2010

NOAA Teacher at Sea Donna Knutson
NOAA Ship Oscar Elton Sette
September 1 – September 29, 2010

Mission: Hawaiian Islands Cetacean and Ecosystem Assessment Survey
Geograpical Area: Hawaii
Date: September 24, 2010

I Hear Them!

I am in the stateroom writing.

I Hear Them!
September 24, 2010
Teacher at Sea:  Donna Knutson
Ship Name:  Oscar Elton Sette

Mission and Geographical Area:  

The Oscar Elton Sette is on a mission called HICEAS, which stands for Hawaiian Islands Cetacean and Ecosystem Assessment Survey.  This cruise will try to locate all marine mammals in the Exclusive Economic Zone called the “EEZ” of Hawaiian waters.  The expedition will cover the waters out to 200 nautical miles of the Hawaiian Islands.

Data such as conductivity, temperature, depth, and chlorophyll abundance will be collected and  sea bird sightings will also be documented.

Erin, Sussanah, and Kim working on the array.

Science and Technology:
Latitude: 25○ 13.6’ N
Longitude: 168○ 23.7’ W  
Clouds:  4/8 Cu, Ci
Visibility:  10 N.M.
Wind:  8 Knots
Wave height:  2-3 ft.
Water Temperature: 28.2○ C
Air Temperature:  25.6○ C
Sea Level Pressure:  1021.6 mb
Of the five senses, hearing is the most important sense to cetaceans.  Sea animals depend on hearing to feed and communicate.  In water it is impossible for whales see long distance, their sense of smell is not as developed as in sharks, their sense of taste and touch will not help in traveling through the water seeking food, so therefore the sense of sound has become the most developed.

“Guts” of the array.

Cetaceans whether odontocetes, the “toothed whales” such as the sperm whales and dolphins, or Mysticetes, the baleen whales such as the Bryde’s or humpback whales, have different ways of producing sound.  Because their methods and mouths are different, different kinds of whales produce different kinds sounds with varying frequencies.
Frequency is the number of waves or vibrations that pass a certain point in one second.  People have a hearing range of approximately 150 – 20,000 Hz.  Hertz or Hz is the unit for frequency meaning how many waves are reaching a destination in one second.   People talk within this frequency range and can hear slightly above and below this range.
Cetaceans have a much broader frequency range.  The “toothed whales” produce rapid bursts of high frequency clicks and whistles.  Their hearing range is 250 – 150,000 Hz.  Single clicks are used for echolocation and a collection of clicks for are used for communication.

Erin, Sussanah, Yvonne, Nicky and Kim checking the connections.

The baleen whales have a lower frequency range of about 10 – 31,000 Hz.  They too use sound for echolocation and communication, but the “whale song” often associated with humpback whales is primarily for sexual selection.
When comparing whales to other land animals, they even have a higher frequency range than dogs or bats.  The bat has a hearing range of 10,000 – 100,000 Hz and the dog’s range in 15,000 – 50,000 Hz.  In whales and bats the higher frequencies are used for echolocation.
 Another difference between the land and aquatic animals, is where their sound is transmitted.  Land animals send and receive sound through the air and cetaceans do both through water.  Sound travels almost four times faster through the water. That is the reason whale noises can travel thousands of kilometers.

Listening in.

Whale noise is not the only noise in the ocean. People are making a lot of noise themselves.  With increased noise from ships, sonar, and seismic surveys the ocean is becoming a noisy place. Environmentalists and cetalogists are concerned with the added noise.
Noise may be one of the factors in animal strandings.  The strandings may due to stress from noise, but in some cases cetaceans have had damaged ears.  It is unknown if increased noise levels have caused the ear damage or it is only old age.  This is definitely an area which could use more study.
Personal Log:

A group of sperm whales sound like the patter of rain.

It has been through my observations aboard the Sette, the acousticians have a challenging job! They of course have a love of cetaceans like all marine biologists, and want to locate and study these animals, but they need to work with very sophisticated electronic equipment rather than be out on the flying bridge looking through the “big eyes”. If the equipment is not designed properly, whale and dolphin sounds cannot be detected.
Yvonne, Sussanah and Nicky are the acousticians on the ship.  These young women have had additional adventures over and above others on the cruise, and adventures that they would probably wish they didn’t have to experience.  I am very impressed with their trouble-shooting abilities, their patience and their tenacity!

Each dot is a click, every color is a different animal.

At the beginning of the cruise the acousticians were gifted with a brand new array!  An array is a long clear soft plastic tube containing all the electronic equipment needed to absorb and transmit sound to the sound equipment back in the ships lab.  The array had (notice I said had – past tense) hydrophones and transmitting boards throughout its 50 foot length.  In order for the sound to travel through the water and be received by the array, the entire electronic circuitry inside the array needed to be immersed in a liquid similar to salt water’s density.  If the electronics were exposed to sea water there would be too much corrosion for the system to work properly. So, they chose a colorless oil to fill the array. The array is laid out on the fantail (back deck) bridge and is connected to a spool of power and relay cords (ok, you realize by now I know virtually nothing about electronics) and then the cords are slipped into the lab and connected to the sound equipment.  I know that last part for certain, because I helped Nicky wire tie them together at the beginning of the cruise.

Dawn listening to the sperm whales.

When the array was (yes, still past tense) lowered into the water behind the ship, it was 300 m back and 6 m deep.  It needed to get a long way past the boat, so the boatnoise wasn’t the only thing heard.  Unfortunately the acousticians could not pick up the normal ocean sounds and animal clicks that they have become accostumed to on past cruises.They looked at the inside equipment, took out boards, tested solders, and electrical power strips.  They checked out the transmitters, connections and screws.  (They reminded me of the Grinch not overlooking one last detail!)  Still the blasted thing did not work.  I hate to admit that I shyed away from them for a time, because all the help I could provide would be in giving inspirational clichés, and I know they had enough of those already. Eventually, enough was enough and even though, and yes remarkably so, they were in good spirits, time had come to take the array apart.  Erin was there to assist, and Kim the Sette’s electronic technician was working side by side with Sussanah, Nicky and Yvonne.  They gutted the whole thing, oil and all.  Then they checked the mini-microphones and relay boards.  I was very impressed!

You could hear the sperm whales loud blows.

All was done that could be so it was decided to put it back together, and try it again.  It worked!  I wasn’t surprised but rather amazed!  Unfortunately two of the four hydrophones stopped working.  Each hydrophone picks up different frequencies so if they don’t all work.  The array doesn’t work. Drat! Not to be overcome with minor setbacks.  (Minor to them, I’m thinking definitely Major if I had to work on it!) The acousticians set to work making an entirely new array!  One day I decided to stop down in the lab to check things out and see what new adventures they were presented with.  As Sussanah sat and stripped wires, I asked Yvonne and Sussanah how much electronic background they had to have for this job because I was clearly impressed.  Neither of them has had any classes, only the experience of working on similar equipment in the past.

Sperm whales use echolocation to find food. This is what you see before they make their vertical dive.

None of them had an electronic background, but they decided to make a new array themselves with the left-over parts. They were determined to become an active part of the survey team!   And they did it!  They built their own array!  It was (yes drat, past tense again!) working great until one day it was getting progressively worse. When the girls pulled it in, they noticed it had been bitten!  Some fish came up behind it and bit the newly fabricated array!  What kind of luck was that!   Salt water was leaking in.  “How can you fix that?” I asked Sussanah at dinner.  She said, with her British accent, (which is so much fun to listen to, and one of the reasons I like to ask her questions) the kevalar material inside the device, which is giving the new array strength and structure, is acting like a wick and soaking up the salt water.  So they split the kevalar and it is being held together with a metal s-connector to try and stop the wicking.

Ernesto, Adam and Juan Carlos gave a valiant effort. Unfortunately no biopsy samples were collected.

It will hold for the next six days until we can get back to port.  Wow, for all the adventures/troubles they are picking up some good information!  The array will receive the sounds from the “toothed whales” but to pick-up the lower frequencies from the baleen whales, the acousticians send out a sonobuoy.  A sonobuoy  is an independent device that is dropped over board, and floats on the surface while sending the signals back to the ship. As I am writing this I am told the acousticians are hearing pilot whales!  They can not only hear them, but can also tell where the whales are at!  I need to go check it out!  They are truly an amazing group of young women.  Even though I have known them for only for a short time, I am truly proud.  Their hard work has definitely paid off.  Their determination is to be admired

Natalie Macke, August 25, 2010

NOAA Teacher at Sea: Natalie Macke
NOAA Ship: Oscar Dyson
Mission:  BASIS Survey

Geographical area of cruise: Bering Sea
Date: 8/25/2010
The Sounds of Science…
Weather Data from the Bridge :
Visibility :  10+ nautical miles (Wondering what a nautical mile is??)
Wind Direction: From the ESE at 8 knots
Sea wave height: <1ft
Swell waves: NW, 1-2 ft
Sea temp:6.8 oC
Sea level pressure: 1018.1 mb
Air temp: 8.2 oC
Science and Technology Log: 

Acoustician, Sandra Parker-Stetter on the Bridge preparing to fish..

When you walk into the acoustics lab you are greeted with an impressive display of primary colors and fascinating images.  Sandy, our Acoustician is also there to greet you and help explain the science behind the images of sound.  She explained not only the basics of acoustic science; but also shared some fascinating biological phenomena that can be witnessed with this technology.

So first some basics about the acoustics.  (Hoping BTW to make Sandy proud about her skills in teaching a physics phobic..   She only made my head hurt a few times..)  When you walk in the Acoustics Lab on the Oscar Dyson you will see there are six different acoustic displays in the lab:

  • 18 kHz & 38 kHz on one display  (These are more common to fishing vessels to distinguish larger fish from jellies, zooplankton and juvenile fish)
  • 70 kHz, 120kHz, 200kHz and a 70 kHz with a sideway view from the ship.

The acoustic sounders positioned on the ship’s centerboard emit a ping that is transmitted directly downward from the boat (except one 70kHz pointed sideways).

These pings each have a set characteristic frequency designated by the unit of a kiloHertz (kHz).   A  kilohertz simply is the thousands of cycles per second that the wave is transmitted.  Frequency is indirectly related to wavelength.  So if you think about what will fit in-between the waves in the left image it will make sense that lower frequency acoustics are used to identify larger things, while higher frequency captures images of much smaller species or individuals.

Acoustics have the potential to not only identify schools of fish, but also discriminate between species types as well.  A characteristic scattering is observed from different types of fish depending on their internal structure (morphology) and composition.  For example, whether or not a fish has a swimbladder can be used for identification.  A swimbladder will cause a greater acoustic scattering.  In terms of composition, jellyfish are over 99% water.  The more like the composition of water, the less the sound bounces off the specimen.  Therefore, the scatter from the ping of the acoustics is weak and difficult to see on the monitor.   However, the jellyfish signature is shows up quite strong on the acoustic monitors.  In this case, the size and shape of the jellyfish causes the sound to scatter regardless of its’ composition.  So acoustic analysis is not always as straight-forward as the scientists (and fishermen) would like.  So how do the scientist tell a jellyfish from a juvenile salmon?  Trawling data..   Part of the acoustic’s mission on our BASIS cruise.  The scientists would like to develop patterns to match trawls with acoustic signals.  Therefore, acoustics can be used in the future more effectively to track and monitor pelagic populations.

 Biological Phenomena Visualized with Acoustic Technology

Biological Phenomena Visualized with Acoustic Technology

Zooplankton Migration 
Using the 200kHz acoustics, tracking the movement of the zooplankton is quite easy.  In the image to the left, taken and archived during the evening hours you can literally see how the zooplankton migrate toward the ocean surface as the sun sets(Around 10PM in these parts..).   Trying to avoid their predators, the zooplankton stay near the ocean bottom during the daylight hours, but migrates upward toward their food source, the phytoplankton, once darkness begins to onset.

Riding the Pycnocline
Another interesting physical oceanographic feature you can observe with acoustics is the pycnocline.  While you can’t literally see the density change of the water using the acoustics aboard this ship, you can watch the fish hover immediately above this feature.

18 kHz Acoustics

38 kHz Acoustics

Personal Log:

Sunset

Sunset

Yesterday morning’s sunrise was one for the books..  Tuesday was a glorious, sunny day aboard the Dyson.. (Uh..  the answer is YES..  apparently Alaskans do sunbathe in 50 degree weather.  As long as the sun is out…  I won’t mention any names.)  The daytime turned to an evening with a sky full of stars.  We then were treated to a spectacular sunrise the next morning with beautiful calm seas.  Thanks to Sandy, who captured the picture to the left that morning, while most of us were busy eating omelets and pancakes in the Mess Hall.

It’s fun sometimes when Sandy’s right….

Brian Beckman, Fish Biologist

After days of searching for the juvenile salmon, we finally found their playground.  One of trawls yesterday brought us over 2,000 sockeye juveniles along with a mess of jellies…  After accosting my colleagues with a few paparazzi moments, it was fun to join in to help sort out the catch.   And even sometimes when things don’t work out perfectly, finding what you’re looking for makes everything better. To the right is a snapshot of what happens when the bin doesn’t stop in time and the fish/jelly mess overtakes the belt and scientists.  Now this is fishin’….

“Catch of the Day…”

Story Miller, July 27, 2010

NOAA Teacher at Sea: Story Miller
NOAA Ship: Oscar Dyson

Mission: Summer Pollock III
Geographical Area: Bering Sea
Date: July 27, 2010

Time: 1940 ADT
Latitude: 60°28N
Longitude:177°51W
Wind: 8 knots (approx. 9.2 mph or 14.8 km/h)
Direction: 270° (W)
Sea Temperature: 9.2°C (approx. 48.6°F)
Air Temperature: 9.1°C (approx. 48.4°F)
Barometric Pressure (mb): 1007
Swell Height: 1 foot (about 30.5 cm)
Wave Height: 0-1 foot (about 30.5 cm)

Scientific Log: 
Me with a pollock

Me with a pollock

There are many different groups of people working aboard the ship, Oscar Dyson – Scientists, NOAA Corps officers, Deck Hands, Engineers, Survey Technicians, and Cooks. Within the science department, there are 12 members aboard and two Teachers at Sea which totals to 14 souls. For this third leg of pollock surveys, the chief scientist is Taina Honkalehto. Her job aboard the ship is to plan the scientific activities and make the decisions on how best to carry out that plan. Of the scientist crew, there are two Russian scientists that are conducting their own research in collaboration with NOAA.

This pollock survey, which focuses on determining abundance and distribution, is an important component of the fishing industry in the United States. According to The Bering Sea Project, “The largest concentrations of pollock occur in the eastern Bering Sea,” and more specifically, “Walleye pollock support the largest single commercial fishery in the U.S., producing the largest catch of any one species inhabiting the 200-mile US Exclusive Economic Zone.” Additionally, the pollock industry is incredibly important to the people living in Dutch Harbor and Unalaska because pollock is one of the main fishes processed there and has helped classify Dutch Harbor as America’s #1 fishing port in the USA for fish landed (NOAA, 2009).

View of a spread out group of pollock as seen from
the computer screen. Notice in the far right corner a
red spot. That shows that at that location,
the fish are densely packed. The red, yellow,
and green-blue line represent the seafloor.

There are two summer surveys being conducted to estimate the Bering Sea pollock population: Acoustic-Trawl Survey and the Bottom-Trawl Survey. Currently on the Oscar Dyson we are conducting the Acoustic -Trawl Survey. After we catch the fish, we combine the acoustics, fish samples, and CTD deployment data, to draw conclusions that help us estimate population size and ecological factors of pollock. Remember, in order for pollock to live where they do, they need food and so when we extract stomach samples, we are looking for what pollock prey upon (mostly krill). Besides, food, other important aspects of their habitat must be in place for their survival. The CTD data –  water temperature, salinity, nutrients, oxygen, and chlorophyll – help us understand how the distribution of pollock has changed in past years and may also provide information about how it could change in the future.

However, not all of the scientists on board are collecting data related to pollock. Currently we have two other subgroups with one observing seabirds and the other observing marine mammals. The crew observing seabirds have a goal of observing species seen during the tour to determine seabird species distribution and abundance. The marine mammal observers are working to obtain current data on cetacean species distribution and abundance.

The Teachers At Sea (TAS), which currently include Obed Fulcar (New York, New York) and myself (Dutch Harbor, AK) have an important role of working under the scientists and other crew members to learn about the research being conducted in an attempt to bring real science into the classrooms.

A large group of fish scattered about from the perspective of the transducer.

Because acoustics is a major tool used in pollock survey, I feel it would be beneficial to provide a few details on how it works. Remember, referring to Blog #2 “the ship has Transducers that send pings of sound energy down through the ocean and when they hit some object, such as the bottom of the ocean or a fish, in this case they are hitting the swim bladders of the fish, some of the energy in the sound ping is returned to the ship and received by our echo sounding system in the acoustics lab of the ship.” It is important to note that the acoustics under the water are different than in the air because the pressure in each location is different. Inside the acoustics lab there are many different screens that display the pings at different frequencies of sound waves. We know that jellyfish tend to show up the best from the low frequencies. Acoustics is a good tool to use to study pollock because pollock is the primary fish species inhabiting the middle-waters of the Bering Sea shelf. For example, bottom fish are difficult to see because the acoustic signals from the seafloor are too strong and tend to hide the bottom fish signals. Acoustic signals that we see on the computer screen rely on the actual physiological make-up of the fish. Also, the behavior of pollock plays a role in how we can see them acoustically. For example, salmon do not swim in large schools like pollock. When we see large schools of pollock on the acoustic screens, density determines the color – blue usually is reflecting a couple fish whereas red represents a high density of fish – and the shape of the schools tend to be typical of pollock. Through acoustics, we are able to survey pollock over a wide area and gain information regarding their distribution and population.

Prior to fishing, we consistently monitor the screens as the ship travels up and down the rectangular transects you can see when you view the ship’s path on ShipTracker. When we observe schools of fish, we need to decide whether they are large enough to sample the fish with the trawl. Because we also want to target certain ages of fish, it is important to be able to estimate their size.

We can estimate size through a method using additional measurements from the acoustic data. We draw a box around an area that is not densely packed with pollock so it is easier to distinguish an individual acoustic image of a fish. The software we have gives us the average intensity of the acoustic pixels. We call this intensity target strength which translates to the size of the echo. Because the size of the swim bladder is proportional to the size of the fish, we can use the intensity of the echo off the swim bladder to estimate the size of the pollock. In short, target strength depends on the size of the swim bladder and features of the swim bladder can be used to predict fish size.

Acoustic image from the bridge. The bottom blue streak is a large group of fish that ducked under the net. The horseshoe shape is the net. The blue inside the horseshoe are the fish.

We can use an equation for calculating decibels to help us estimate the size of the fish in the school we might target.  For my friends and students who are math gurus, the equation is TS = 20Log(length cm) + b20. The b20 variable is different for different fish species and so for Walleye Pollock in the Bering Sea, b20 is -66. Therefore, the equation for Walleye Pollock is TSpollock = 20Log(length cm) – 66.

To provide an example of how the equation works, lets say that the average length of a two year-old pollock is 25 cm and that is the size we want to target. We take that 25 centimeters and “plug it” into the section of the equation that stands for length in centimeters. Scientific calculators are wonderful devices for logarithms as they have the Log function already installed, and if you plug in 20Log(25) – 66 into the calculator, the answer -38.4 translates into the target strength that would show up on the screen. So if we find schools of pollock and see that the target strength is close to -38.4, then we know the echosounder is observing two-year old pollock.

Once acoustics have determined that we need to fish, they send the coordinates they want the Officer of the Deck (OOD, a.k.a. the NOAA Corps officer on watch on the bridge) to follow and the officers drive the ship to the location. On the bridge of the ship, the scientists are able to see the acoustic screens and are able to keep an eye on the location of the fish, relative to the transducer underneath. From there the Lead Fisherman or Chief Bosun operates the machinery required to put the trawls in the ocean. After the large mesh net is placed in the ocean, the crew put on a sensor that measures water depth and temperature. They also install a tool, called a headrope unit, that is similar to a mini transducer which makes an image of the mouth of the net and allows the scientists to watch fish entering the net from the bridge.

Senior Survey Technician, Kathy Hough, and Ordinary Seaman, Frank Footman, installing the head-rope unit.

Once the fish are caught, the deck crew will draw the nets back onto the boat using hydraulics. From the stern (back of the boat), the fish go into the fish lab on a conveyer belt where we sort, sex, measure, and extract stomachs and otoliths. Since being on the ship, during my shift we have been averaging two trawls per day.

How is the information we collect used?
On the ship, we are collecting raw data, entering into our computers, and analyzing what we see. From there, we can draw conclusions based on what we have observed from our samples. However, there are other scientists at work here. For example, perhaps you are interested in working with computers and want to be involved with wildlife. Some of the scientists help design the computer programs we use and maintain them. Perhaps boat life is not your “cup of tea.” All the stomach and otolith samples we collect need to be sent into a lab to be analyzed by a stomach or otolith expert. The data they compile from the samples we collect get added into our publication at the end of the survey. There are also scientists that compile our conclusions about what we saw on the ocean and they create models to show population trends and predict future abundance. From that information, a council of scientists, industry representatives, and others of interest, get together and determine things such as fishing quotas. Also, don’t forget that there are teachers, like me, aboard who take some of the scientific information or scientific processes and educate students about real science in the real world.
If you want to obtain a job working in the sciences department of NOAA, some courses of study that will increase your chances of becoming involved include but are not restricted to: Marine Biology, Chemistry, multiple levels of mathematics, Computer Science, Writing. Versatility is another key factor to consider for any job you may want to pursue as the more background information you have, the more information you can “bring to the table.” For example, perhaps you love music. An understanding of decibels and how sound is carried at different frequencies is incredibly useful in acoustical sciences. Foreign Language is always beneficial as you will continually work with people from all over the world and remember, there are two scientists currently on the ship who are from Russia! Therefore, in my opinion, don’t forget about your electives when choosing your courses because the more rounded you are, the greater your chances are for success!
Personal Log:

My morning started off fantastic as I was able to launch an XBT into the water again. By the time I was beginning to type this blog we passed over a school of pollock and decided that we needed to turn around and go fishing. Approximately two hours of sorting commenced before I was able to return. I learned that acoustics is a very difficult concept to explain as there are many factors in mathematics and physics that are complicated to translate into layman’s terms. I ended up spending a lot of time reading a textbook on the research the theories of using acoustics on wild fish. Please do not hesitate to ask in the comment box below this post if you have questions!!!

Overall, there was a good assortment of fish today and I stayed fairly busy in the fish lab collecting pollock sample data!

Me giving the fish a layer of water so that they slide down the
chute and onto the conveyor belt easier.

Animals Seen Today:
Walleye Pollock
Silver Salmon
Northern Fulmar
Parakeet Auklet
Short-tailed Shearwater
Least Auklets
Tufted Puffin
Thick-billed Murre
Northern Fur Seal

Something to Ponder:
Life at sea can be an amazing experience but there are many things people may take for granted when living on land. For example, consider the possibility of becoming hurt on the job, or developing a medical condition such as a rash or appendicitis. From the middle of the ocean, it is very difficult to reach a doctor to get a diagnosis. On board the ship, we have some medical supplies but typically there is not a licensed doctor on board the ship. Would you know how to respond to an emergency if it were to happen? If you have taken a First Aid or CPR class, do you remember what you need to do? How would you react? What would you do to reach help? Who could respond to your call?
For the Oscar Dyson we have the following protocols:
1. Contact the medical officer on board for an initial diagnosis.
2. If the condition requires advanced medical care, he or she will contact the medical officer on call at the NOAA Marine Operations Center.
3. In the case of an emergency and when the Marine Center cannot be contacted, he or she will contact the Maritime Medical Assistance (MMA).
4. If needed, we will arrange for a medevac (medical evacuation) which could involve the US Coast Guard and/or head back to port.

Wesley Struble, 23 July, 2010

NOAA Teacher at Sea
Wes Struble
Onboard NOAA Ship Ka’imimoana
July 8 – August 10, 2010

Mission: Tropical Atmosphere Ocean (TAO) Cruise
Geographical area of cruise: Equatorial Pacific from 110 degrees W Longitude to 95 degrees W Longitude
Date: Friday, 23 July 2010

Weather Data from the Bridge

Current location: 4 degrees South Latitude & 110 degrees West Longitude
Cloud Cover: 5/8
Cloud Type: Stratocumulus
Visibility: 10 nautical miles
Wind Bearing: 100 degrees
Wind Speed: 20 Kt
Wave Height: 2 feet
Swell Height: 5 – 7 feet
Barometric Pressure: 1015.5 mb
Temperature: 24.8 degrees C (76.6 degrees F)

Science and Technology Log

There are a variety of buoys used by NOAA in the Pacific Ocean. One of the more interesting is the ADCP buoy. ADCP stands for Acoustic Doppler Current Profiler. This buoy is anchored to the sea floor like most of the other buoys deployed on this cruise. The major difference is that the ADCP buoy does not float at the surface but rather is tethered with a line short enough to keep it submerged approximately 300 meters below the surface of the sea. In addition, it is only deployed with the TAO buoys at the equator and not at any of the other TAO buoy locations. The buoy’s name defines its function – current profiling – using acoustic signals (similar to sonar) the buoy provides a profile (or vertical map) of the ocean currents from the depth at which the buoy is tethered to the surface. The ADCP is able to measure both the speed of the current and the direction in which it is moving. Even though the TAO buoy at the same latitude is generally visited more often, the ADCP buoy is visited only once per year. During the visit the buoy is retrieved, cleaned, damaged parts replaced or repaired, data downloaded, batteries replaced, and sensors upgraded (if necessary).

Buoy with newly attached ADCP unit – A

KA skiff at the ADCP buoy

The flotation component of the buoy is a large orange sphere just over four feet in diameter. This float is made of syntactic foam. In general, foam is a mixture of two substances: a gas phase in a solid or liquid phase. Syntactic foam should not be confused with the common foam with which we are all familiar (like the typical Styrofoam coffee cup). Most of these foams are generally composed of expanded polystyrene (a thermoplastic polymer) where the gas phase is air and the solid phase is polystyrene. Syntactic foams on the other hand use other substances for the components.

The ADCP acoustic transmitters & receivers

One of the more common syntactic foams uses small glass spheres 10 – 200 micrometers (millionths of a meter) in diameter. These glass spheres are filled with air during the manufacturing process. The spheres are then mixed in with some type of epoxy resin and allowed to cure to produce the foam. The buoyancy of the foam is affected by the size, number, and wall thickness of the glass spheres. Some of the applications that typically utilize syntactic foams are the manufacture of radar transparent materials, acoustic attenuating materials, and more specifically deep sea buoyancy floats. Our float is anchored to the sea floor with a large (several thousand pound) weight that prevents it from drifting. The material used to attach it to the anchor is very stable and exhibits little elongation under tension, thus keeping the buoy consistently at the same depth. The payload (the ADCP itself) is approximately 1 meter long and about 20 centimeters in diameter and is mounted in a circular well that is bored vertically through the center of the float. The ADCP has four sending/receiving units mounted at the top of the main body. One can see these in the photographs. These units send and receive a 75 kHz signal that reflects (echoes) off the sea/air boundary and returns to the buoy.

When we were close to the location of the ADCP buoy one of the scientists activated an acoustic trigger that released the buoy from its sea floor mooring anchor. Since it was almost 1000 feet under water it took a few minutes for the float to reach the surface. When the buoy was spotted the ship made a slow pass to visually inspect the float and to launch the skiff. The skiff towed a long and very strong line from the ship which was then attached to the top of the buoy. At this point the skiff was brought back aboard. The ship then came about so that the buoy was directly a stern. When all was ready the winch began to retrieve the line and slowly bring the buoy on board. When it reached the deck of the fantail it was made secure and the tether line (that attached the buoy to the anchor) was tied off to a chain on the ship’s deck.

Working on the ADCP buoy on the fantail of the      KA – B

The buoy was then disconnected from its tether line and the line was attached to a large winch and all several thousand meters of it was rolled onto a number of large empty spools and stored on board. While the anchor line was being retrieved the science crew downloaded the stored data from the ADCP and prepared the buoy for redeployment. When the deck hands were ready the process was reversed. First, the tether line was attached to the buoy and it was lowered over the fantail. Then the line was slowly played out. When the ship was in the appropriate position she began to move forward as the crew played out line. When they reached the end of the line a large (several thousand pound) anchor was attached, lowered, and released. This entire process took the better part of a day.

Crew member Nemo McKay & Scientist Will Thompson retrieving the ADCP buoy

Personal Log

I have enjoyed getting to see the crew work together. One can tell that they clearly get along well and appear to enjoy working together because of all the friendly banter that passes between them. I have been impressed with how conscious they are about safety. I have been able to begin participating in some of the work deck activity during the buoy operations and it has helped in my understanding of what actually takes place. It has also helped me to get to know a number of the crew members better.

“Did You Know?”

Did you know that the greatest buoy equipment problem that occurs in this area of the ocean is vandalism? Many of the buoys are damaged, stolen/cut loose, or destroyed. This might be done either out of anger and frustration, for financial gain (the buoys have quite a large mass of aluminum framing and electronic equipment), or by accident. Regardless of the reason, much time, data, and financial resources are lost and consumed in maintaining TAO array in the Pacific Ocean.

Rebecca Kimport, JULY 12, 2010 part2

NOAA Teacher at Sea Rebecca Kimport
NOAA Ship Oscar Dyson
June 30, 2010 – July 19, 2010

Mission: Summer Pollock survey
Geograpical Area:Bering Sea, Alaska
Date: July 12,  2010

A Floating City

A modern city has a network of companies that provide us with modern conveniences (water, electricity, sewage and trash removal). A NOAA research vessel provides those same conveniences to its crew through the complex engineering network. We wouldn’t be able to eat, drink, take showers, or conduct research without the expertise of our engineers.
Sea water is taken in by an intake valve about 6 m below the surface. It goes through a variety of cleaning processes to filter, distill and purify the water for human consumption. First, small sea creatures are removed by a filter known as the “sea chest.” Here is a picture of some of the creatures captured by the sea chest in the Oscar Dyson. Next, the water is distilled using the heat from the engine under a vacuum to remove dissolved ions. The water is then purified using bromine and UV light before it is pumped into the piping system (running throughout the ship in pipes labeled “potable water”). The water is so pure that we have to add salt for the espresso machine to recognize the water level (the science of the espresso machine will have to wait for a later entry).

Contents of the Sea Chest

Lights, Camera, Acoustics
The Oscar Dyson requires electricity to run the ships instruments, the scientific equipment and the lights which allow us to keep the ship operational 24/7. Our power is generated by the engines which also propel the ship forward. The Oscar Dyson runs on diesel fuel and uses larger, more powerful versions of the engines we find in cars. We use about 110 gallons of fuel each hour to maintain scientific and navigational operations.

Engine

Taking out the trash
Kitchen and food waste are the main sources of trash on the Oscar Dyson. Trash is sorted and disposed of based on how it breaks down. Food, which decomposes, is released into the ocean to re-enter the ecosystem. Combustible items (such as paper, napkins, etc) are burned in the ship’s incinerator which is run every night. Non-combustible items, such as aluminum cans, are recycled and brought back to land.

And out the other end
Although a less than pleasant topic to discuss over dinner, it is important to remember that a ship must track its human waste as well. Per NOAA regulations, human waste is treated through a complex process before being released into the ocean (to re-enter the eco-system). This process, like those of water treatment plants and septic systems on land, break down the waste through multiple steps involving biological, physical and chemical reactions. Ask me for more information if you really want the dirty details.

Who’s watching the engines?
The Oscar Dyson employs an engineering staff of seven, who have specialized training and job responsibilities to ensure proper functioning and maintenance of the vessel. Like all good engineers, they usually work behind the scenes so it was great to get an inside look at the inter-workings of the ship.

New Vocabulary
hull: watertight body of a ship
distill: remove impurities
ions: an atom with a positive or negative charge. Ions are created when elements gain or lose electrons. They can be in the form of a solid or a liquid (dissolved)
UV light: ultraviolet light

Rebecca Kimport, JULY 3, 2010

NOAA Teacher at Sea Rebecca Kimport
NOAA Ship Oscar Dyson
June 30, 2010 – July 19, 2010

Mission: Summer Pollock survey
Geograpical Area:Bering Sea, Alaska
Date: July 3,  2010

Here fishy fishy

In a previous post, I briefly mentioned that acoustics helps Oscar Dyson scientists locate aggregations of pollock. I didn’t know much about acoustics surveying before I arrived on board but think its pretty cool.The Oscar Dyson has 5 transducers on its center board and 1 temporary transducer on the side of the center board that looks horizontally. The transducers allow us to see where the fish are. Because of where the transducers are placed, we can only see the pollock from 16m to the bottom. This means that if there are any fish between the surface and 16m they will not be detected. This is the near surface “dead zone”. At right you will see a picture of the acoustic data picked up by the transducers. Why this happens? The transducers are mounted on the bottom of the centerboard about 9 m below the water line, and near the transducer face (first 7 m), no good data are collected. Why it’s okay? Pollock tend to hang out in mid-water. Although a few baby pollock might be in the near surface “dead zone,” the majority of pollock will be in the area we are watching. There is also a bit of a “dead zone” at the other end near the ocean floor.
Acoustic Data

Acoustic Data

Why acoustics? 
Ideally, the acoustic data collection would allow us to track aggregations of pollock without actually having to fish them out of the water. All parties involved (scientists, fish, bank accounts) would benefit from this change but scientists are still in the process of perfecting this process. The Oscar Dyson is part of a fleet of five boats that was specifically designed for acoustics. Specifically, it is considered a “quiet boat” where the engine noise is decreased to prevent scaring the fish. Other acoustic projects include: Pacific hake off the coast from California to Vancouver Island (run as a joint project with Canada), herring in the northwest Atlantic, and krill in the Antarctic. Acoustics are used throughout the globe and many countries depend on acoustics for their fish surveys.

Sonar

Sonar

Looking in more than one direction
Along with the transducers, there is also a multibeam SONAR that produces the same information as the transducers but with a wider angle range. Scientists use this program to help separate species in the water column. The multibeam ME70 sends its signal out after the transducers information is sent and returned. They alternate about 1.5 seconds apart. Scientists around the world are working to improve this technology and we use information from a group at University of New Hampshire along with a program from Tasmania to analyze these data. Scientists utilize the multibeam ME 70 along with the transducers and fish trawling to ensure they are capturing an accurate picture of the mid-waters.

How the survey data we collect are used.
The data we collect on the Oscar Dyson during the summer pollock surveys are used by scientists and policy makers to determine the fishing quota (the “take”) of pollock for the next season. Quotas are important for maintaining the population of pollock (and other species) for this generation and generations to come. The data we collect on the Oscar Dyson help ensure that maximum stock can be taken without negatively impacting the Eastern Bering Sea pollock population.Thought Question: What could happen if we didn’t regulate the amount of fish that could be caught? Bonus points for anyone who can identify an area where overfishing has impacted the ecosystem.

Michele Brustolon, July 1, 2010

NOAA Teacher at Sea
Michele Brustolon
Onboard NOAA Oscar Dyson
June 28 – July, 2010

NOAA Teacher at Sea: Michele
NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Eastern Bering Sea (Dutch Harbor)
Date: July 1, 2010

Weather Data from the Bridge

Time: 1400
Latitude: 58.19 N
Longitude: 170.01 W
Cloud Cover: 100%, dense fog
Wind: 11.49 knots
Air Temperature: 3.800 C/ 38.840 F
Water Temperature: 3.960 C/ 39.1280 F
Barometric Pressure: 1003.10 mb

Science and Technology Log

Here fishy fishy!
July 1st began by spending time in the Acoustics Lab learning about the equipment used to analyze the data. The Oscar Dyson has 5 transducers on its center board and 1 temporary transducer on the side of the center board that looks horizontally. The transducers allow us to see where the fish are. Because of where the transducers are placed, we can only see the pollock from 16m to the bottom. This means that if there are any fish between the surface and 16m they will not be detected. This is the near surface “dead zone”. Why this happens? The transducers are mounted on the bottom of the centerboard about 9 m below the water line, and near the transducer face (first 7 m), no good data are collected. Why it’s okay? Pollock tend to hang out in mid-water. Although a few baby pollock might be in the near surface “dead zone,” the majority of pollock will be in the area we are watching. There is also a bit of a “dead zone” at the other end near the ocean floor. Yesterday the bottom was around 69.35m.

Transducer data

Why acoustics?
Ideally, the acoustic data collection would allow us to track aggregations of pollock without actually having to fish them out of the water. All parties involved (scientists, fish, bank accounts) would benefit from this change but scientists are still in the process of perfecting this process. The Oscar Dyson is part of a fleet of five boats that was specifically designed for acoustics. Specifically, it is considered a “quiet boat” where the engine noise is decreased to prevent scaring the fish. Other Acoustic projects include: Pacific hake off the coast from California to Vancouver Island (run as a joint project with Canada), herring in the northwest Atlantic, and krill in the Antarctic. Acoustics are used throughout the globe and many countries depend on acoustics for their fish surveys.

A little help from UNH!
Along with the transducers, there is also a multibeam SONAR that produces the same information as the transducers but with a wider angle range. The multibeam ME70 sends its signal out after the transducers information is sent and returned. They alternate about 1.5 seconds apart. The University of New Hampshire (UNH) is helping to use the tool and also to analyze the data. To analyze the transducer data collected, a program is in place from Tasmania to help determine what the boat is seeing. The scientists use the program to help separate species in the water column. Scientists utilize the multibeam ME 70 along with the transducers and fish trawling to ensure they are capturing an accurate picture of the mid-waters.

Multibeam ME70 data

How the survey data we collect are used. The data we collect on the Oscar Dyson during the summer pollock surveys are used by scientists and policy makers to determine the fishing quota (the “take”) of pollock for the next season. Quotas are important for maintaining the population of pollock (and other species) for this generation and generations to come. The data we collect on the Oscar Dyson help ensure that maximum stock can be taken without negatively impacting the Eastern Bering Sea pollock population.

Here I am deploying the XBT (eXpendable bathymetric thermograph)

Personal Log

Although there was no fishing yesterday, I certainly was able to be involved. I launched the XBT off the Hero Deck just as we began our fire drill. Once that was completed I returned to the Acoustics Lab until we were cleared from the drill. We then had our abandon ship drill where we get our survival suits and head to our assigned position. My meeting location is at life raft 3 and 4. Once we learned how to deploy our life raft, we headed inside to the conference/lounge to practice donning our suits. While this is very serious, it is also worth a laugh or two watching people struggle and become orange gumbies! The goal is to be able to don your suit in under 60 seconds!

Zodiac ride into the cove of St. Paul’s Island

Yesterday I had the opportunity to head into St. Paul’s Island; the largest of the Pribilof Islands. St. Paul’s is also called the Galápagos of the north. The Zodiac was driven by Joel Kellogg and Amber Payne, and our CO (Commanding Officer Mike Hoshlyk) allowed Katie, Rebecca, and I the opportunity to take the trip inland. Our mission while on land was to bring science equipment (ice-flow detector) to the airport that needed to be sent to Anchorage. Stepping foot onto St. Paul’s Island seemed eerie and mysterious. There was the lurking fog along with a very industrial feel to the island. Because most of the island consists of coalescing small volcanoes, the sediment’s dark color is due to lava flow which didn’t brighten the land at all. We did not see many people other than those working on dredging the new causeway or the people in the airport. Our taxi driver said that they hadn’t gotten mail since Monday and it was Thursday which explained why the people waiting for flights at the airport seemed a bit anxious. On our way back to the boat, we were able to see sea lions and some puffins hanging out in the water and around the break wall. As we approached the boat, it was like an apparition appearing before us. Just another once in a lifetime chance that I have had this cruise!

Want more information about the Pribilofs? Check out http://www.amiq.org/aleuts.html

Oscar Dyson coming back from Pribilofs

Animals Seen

Auklets
Murre (2 different types differentiated by bill type)
Fox
Puffins
Sea lions

(but no fur seals…everyone told me I would see them but they were missing. It seems to be a question everyone is asking (see
http://response.restoration.noaa.gov/book_shelf/147_puzzle_in_pribilof.pdf )

Word of the day

Desmadre: troublemaker

New Vocabulary

Transducer: instrument used to send out signals that return and show where fish are located
Ground fishing: trawling on the ocean floor

Richard Chewning, June 6-7, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Dates: June 6-7, 2010

Weather Data from the Bridge

Position: Snakehead Bank, Gulf of Alaska
Time: 1700 hrs
Latitude: N 56 00.390
Longitude: W 153 46.380
Cloud Cover: Overcast
Wind: 12 knots from the SE
Temperature: 7.1C
Barometric Pressure: 1016.9 mbar

Science and Technology Log

I have been impressed by the wide array of oceanographic research the Oscar Dyson is able to conduct. A few examples include biological studies of organisms ranging from microscopic plankton to massive marine mammals, collecting a variety of weather data, describing both physical and chemical characteristics of seawater (such as temperature, salinity, chlorophyll, and dissolved oxygen), conducting acoustic surveys of marine life and the sea floor, and much more.

Three Saints Bay nautical chart

One of the Dyson’s ‘bread and butter’ surveys is our survey studying the distribution, biomass, and biological composition (male/female ratios and age) of walleye pollock in the Bering Sea. Walleye pollock is a very important fishery for Alaska. You have almost certainly been a part of this fishery as most fish sandwiches in fast food restaurants and fish sticks in the frozen food section of your local grocery store are Alaskan-caught pollock.

One of the Oscar Dyson’s many tools for this research is her impressive array of acoustic sensors located on the ship’s hull and centerboard. The centerboard is an extension of the hull that can be raised and lowered in the water in order to position most of the Dyson’s sensitive acoustic sensors below the bubbles often found near the water’s surface. These air bubbles interfere with sound traveling through the water and degrade the quality of the data being collected. The Dyson has six downward looking centerboard-mounted transducers, each transmitting a different frequency. Why so many frequencies? Since different types of marine organisms interact with sound waves differently producing varying acoustic signatures, the Dyson must be equipped with a variety of sensors to best characterize the variety of marine life encountered during a survey.

For example, lower frequencies are better suited for fish such as pollock and the higher frequencies are better suited for smaller organisms such as plankton. Think of transducers as a downward shining flashlight illuminating the depths of the ocean with sound rather than light.

The Dyson also has other acoustic sensors such as the ME-70 multibeam echosounder that has the unique ability to look over a much wider angle through the water. Acoustic research works on the same echo location principle that bats and marine mammals employ to find food and navigate. By sending out sound waves and measuring the time the sound takes to travel back after encountering an object, one can learn a great deal about that object’s properties such as distance, size, and movement.

Before traveling to the Bering Sea to start our pollock survey, the Dyson’s scientists must take great care to ensure that their echo-sounding equipment is calibrated correctly. Calibrating the transducers is similar in concept to tuning a piano string or zeroing a sight on a rifle. To this end, the Dyson anchored in Three Saints Bay, a sheltered bay protected from the wind, waves, and currents of the open ocean, at least theoretically. While a troublesome storm passed almost directly overhead, scientists from the Midwater Assessment and Conservation Engineering (MACE) Program (part of the Alaska Fisheries Science Center (AFSC) located in Seattle, WA), the US Fish and Wildlife Service (FWS located in Anchorage, AK), and the Pacific Institute of Fisheries and Oceanography (located in Vladivostok, Russia) worked diligently to fine tune their acoustic sensors.

Copper sphere used to calibrate the acoustic sensors

Bill and Patrick positioning spheres under the Dyson

Paul Walline, Patrick Ressler, Darin Jones, Bill Floering, and Mikhail ‘Misha’ Stepanenko worked day and night calibrating their equipment using metal spheres positioned directly under the ship.

Spheres of different sizes and materials with known acoustic signatures (such as tungsten carbide and copper) are used to calibrate the transducers.

The crew of the Dyson works around the clock as ship time is precious. The scientists work 12 hour shifts, either from 4am to 4pm (the shift to which I am assigned) or from 4pm to 4am. The acoustics lab where the data is collected and analyzed is affectionately called ‘The Cave’ as there are no portholes (windows) to tell the time of day outside.

The acoustic lab, a.k.a. “the cave”

Personal Log

I wasn’t sure when the Dyson arrived at Three Saints Bay as I had retreated to my stateroom early in the evening of the 4th as I was feeling the effects of the rolling seas. I am being berthed with the ship’s 2nd Cook, Floyd Pounds, who is also from Georgia but now calls the Dyson home.
Floyd works with the Chief Steward, Rick Hargis, who has been with NOAA for 20 years and is originally from Washington State. So far the meals have been very filling and satisfying (there is even an ice cream bar!).

My stateroom is located on the crew deck, one level below the main deck near the bow (the pointy end of the ship) on the starboard side (the right side when facing the bow). Utilizing every nook and cranny and with no wasted space, my berth is quite cozy and is surprisingly comfortable. Fortunately with the help of some seasickness medication, I soon found my sea legs and awoke feeling refreshed and hungry (always a good sign!). Seasickness comes from conflicting messages received from the inner ear and the eyes by the brain (the inner ear feels the motion of the boat rolling and pitching in the water but the eyes report a stable environment confusing the brain).

Snug as a bud in a rug

Richard, ready for a swim

A person soon observes that safety is paramount onboard the Dyson as with any NOAA vessel. For example, within 24 hours of leaving Kodiak, the entire crew conducted fire and abandon ship drills. These drills are conducted once a week and are essential for maintaining readiness in the event of an emergency. During the abandon ship drill, I was able to practice donning my survival suit just like our visiting Coast Guard kids did in Kodiak! Although the suit is designed to be quite snug to keep cold water out and to keep the body warm, I was thankful I didn’t have to put the suit to the test by going over the side. To my surprise, Chief Marine Engineer Jerome ‘Jerry’ Sheehan and ENS Russell Pate did just that, going for a dip in the frigid 7.3 degrees Celcius or ~45 degrees Fahrenheit waters! Jerry and Russell used dry suits to scuba dive under the Dyson to check the hull, the prop, and the transducers for anything out of place such as barnacles on the transducers or tangled fishing gear. The only discovery was of a piece of bull kelp snagged on one of the blades of the prop which may explain a noise that was heard on the hydrophones (microphones located under the Dyson’s hull) during our departure from Kodiak.

CO Hoshlyk overseeing recovery divers Jerry Sheehan and ENS Russell Pate

After completing our calibrations and safety operations, the Dyson sailed for a site called Snakehead Bank located 60 nautical miles southeast of Kodiak. The name comes from the bathometric profile of the seafloor of this area which resembles the head of a snake. We soon began conducting camera operations for ground-truthing sea floor composition that I will discuss in my next log!

Remnants of Nunamiut, earliest Russian settlement 1792 in three saints bay, Kodiak

Departing Three Saints Bay

 

Where did the NOAA ship Oscar Dyson’s name originate?

 

The Oscar Dyson is named for an Alaskan fisherman who was very influential in fisheries development and management in Alaska. From his days as a commercial fisherman, Oscar Dyson was a pioneer and advocate for Alaska fisherman and was very influential in the growth of this important industry. Alaska’s commercial fishing industry spans the state and includes salmon, herring, pollock, various shellfish, and various ground fish like halibut. While traveling through the Ted Stevens International Airport in Anchorage, I learned that Alaska is a land defined by water with more than three million lakes and more coastline than the rest of the United Sates combined! Alaska is also the only state in the US to have coastlines with three different oceans/seas: the Pacific Ocean, the Arctic Ocean, and the Bering Sea.

Karen Matsumoto, April 25, 2010

NOAA Teacher at Sea: Karen Matsumoto
Onboard NOAA Ship Oscar Elton Sette
April 19 – May 4, 2010

NOAA Ship: Oscar Elton Sette
Mission: Transit/Acoustic Cetacean Survey
Geographical Area: North Pacific Ocean; transit from Guam to Oahu, Hawaii, including Wake Is.
Date: Friday, April 25, 2010

Science and Technology Log

The Oscar Elton Sette is making its way to Wake Island, and we hope to be there by tonight. One of the research operations is to recover a HARP (High-frequency Acoustic Recording Package) that is in place on Wake Island and replace it with a new HARP unit.

This morning, I was on “CTD duty” at 4:30 a.m. A CTD (conductivity-temperature-depth) station is deployed prior to the start of the visual survey effort, right at sunrise. The CTD data is collected using the ship’s SeaBird CTD shown below. The CTD is deployed to a depth of 1000 meters (depending on depth where we are) with a descent rate of about 30 meters per minute for the first 100 meters of the cast, then at 60 meters per minute after that. It takes three people, plus a winch driver to deploy the CTD, as well as the expert operation from the bridge to keep the ship steady and in one place during the entire operation!

Checking the CTD unit prior to launch.

Launching the CTD unit.

Background on CTDs

The CTD is a device that can reach 1,000 meters or more in depth, taking up to five water samples at different depths, and making other measurements on a continuous basis during its descent and ascent. Temperature and pressure are measured directly. Salinity is measured indirectly by measuring the conductivity of water to electricity.

Chlorophyll, a green photosynthetic pigment, is measured indirectly by a fluorometer that emits purple light and measures fluorescence in response to that light. These measurements are made continuously, providing a profile of temperature, salinity, and chlorophyll as a function of depth. The CTD unit is torpedo-shaped and is part of a larger metal water sampling array known as a rosette. Multiple water sampling bottles are often attached to the rosette to collect water at different depths. Information is sent back to the ship along a wire while the instrument is lowered to the depth specified by the scientist and then brought back to the surface.

Monitoring the CTD in the ship’s E-lab.

Data gathered from the CTD during its descent.

By analyzing information about the water’s physical parameters, scientists can make inferences about the occurrence of certain biological processes, such as the growth of algae. Knowledge like this can, in turn, lead scientists to a better understanding of such factors as species distribution and abundance in particular areas of the ocean.

I am continuing my acoustic work with the sonobuoys. Today I heard a Minke whale BOING! Below is what a Minke whale boing looks like on the computer. It sounds very much like someone blowing a low tonal whistle or a cell phone vibrating on the desk!

 

To hear an Atlantic minke whale call (which is different from those found here in the North Pacific, but really cool!) go to this website:

http://www.pmel.noaa.gov/vents/acoustics/whales/sounds/sounds_atlminke.html

Personal Log

I am making so many great friends among the Sette crew and the science team! I am getting spoiled from all the fantastic meals put together by Randy our cook, and no one ever wants to miss a meal! Our wonderful Doc Tran makes incredible Vietnamese dishes and delicious desserts. Today we had cream puffs for dinnertime dessert! Who would have ever guessed!

Marie Hill, our Chief Scientist and fearless leader was awarded the prestigious NOAA Team Member Award! We surprised her with balloons and decorations in her cabin, and Doc Tran and Lisa made a yummy cake in celebration! Congratulations Marie!!!

Marie Hill, Chief Scientist finding her cabin wildly decorated to congratulate her on her award.

We had a visitor today on the flying bridge-an exhausted juvenile red-footed booby! He sat on the mast, finding a place to rest in the middle of the ocean! It felt great to feel the warm wind hit my face and watch the sapphire blue water crash against the bow of the ship! What a great feeling!

Juvenile red-footed booby on the bridge

Deep blue Pacific ocean water!

Question of the Day: How can you figure out how much food to bring on a 2-week cruise? How do you keep the food fresh? What do you do with leftovers?

This is the situation that the Chief steward has to deal with on every cruise! How would you figure this out? Can you do the math?

New Term/Phrase/Word of the Day: Beaufort Sea State is an empirical measure for describing wind speed based mainly on observed sea conditions. It is also called the Beaufort Wind Force Scale. We stop conducting our visual observations when wind/sea conditions reach Beaufort 7, as wind and sea conditions are too rough to accurately make observations (and its windy out there!).

Something to Think About:

This part of the North Pacific is often described as an ocean desert. We have not seen any whales, and have had only a couple sightings of dolphins since we left Guam. We have also seen migrating sea birds, but not in huge numbers. What do you think may account for the lack of sea life in this expanse of tropical waters?

Animals Seen Today:

  • Sooty tern
  • Red-footed booby (juvenile)

Did you know?

That the team of whale visual observers never discuss the numbers of animals they see among themselves. Some people consistently count high, others count low, others are spot on! By not discussing how many animals they observed, they don’t influence each others’ observations. Back at the lab, researchers compare each observer’s counts from their written observations, and can tell which observers tend to under or overestimate numbers of animals they see. They can then make adjustments to total numbers based on everyone’s observations! This is similar to calibrating thermometers or other scientific equipment!

Today’s sunset from the Sette.

Karen Matsumoto, April 19, 2010

NOAA Teacher at Sea: Karen Matsumoto
Onboard NOAA Ship Oscar Elton Sette
April 19 – May 4, 2010

NOAA Ship: Oscar Elton Sette
Mission: Transit/Acoustic Cetacean Survey
Geographical Area: North Pacific Ocean; transit from Guam to Oahu, Hawaii, including Wake Is.
Date: Friday, April 16, 2010

Science and Technology Log

The research mission for this cruise is to follow a transit from Guam to O‘ahu, Hawai‘i via Wake Island, and conduct an acoustic (hearing) and visual (seeing) survey of cetaceans (whales and dolphins) along the way. A transit is similar to a transect line you use to monitor our beaches in our nearshore studies! This transit study will be conducted from April 19 to May 4, 2010. This project represents important and groundbreaking research for whale biologists, since very little is known about the distribution and vocal behavior (the sounds made by whales) of baleen whales in this part of the Pacific.

Our research mission has several objectives:

  • Collect data on the presence of whales/dolphins and their abundance (how many)
  • Collect tissue samples from whales/dolphins for genetic studies
  • Collect photo identification on any whales/dolphins observed
  • Collect acoustic (sound) data on whales/dolphins to help in species identification and understanding their vocalizations
  • Collect acoustic data on fisheries to understand the distribution of prey species along the transit line
  • Recover and install underwater acoustic monitoring equipment, called a HARP (High-frequency Acoustic Recording Package), near Wake Island that will remain there for a year.

The research team consists of 12 scientists who are trained in visual observations of cetaceans and acoustic monitoring. I am part of the research team, and will fill in for staff conducting the visual observations and routinely conduct the acoustic monitoring.

The visual observation team consists of eight biologists rotating between four stations: Two “big eye” (25 x 150) binocular stations, one on the port (left) side and one on the starboard (right) side; one station forward observing with the naked eye and 7X binoculars; and one station rear-facing looking behind the ship with naked eye and 7X binoculars. Scientists work on 2-hour shifts and rotate among the scientists.

Visual observation station on flying bridge.

Research team member Adam on a “Big Eye”.

The acoustic team monitors whale vocalizations using two different methods. One method uses a hydrophone array towed behind the ship 24 hours a day (mostly to monitor toothed cetaceans, including dolphins). This hydrophone array is similar to the ones installed at Seattle Aquarium, Neah Bay, and other locations to monitor orcas and other whales in Washington State.

The other acoustic monitoring method uses Navy surplus sonobuoys (which were originally developed to detect submarines) that are launched three times a day at 0900, 1300, and 1700. The sonobuoys have a wide range in frequency response. They are able to pick up sounds between 5 Hz (cycles per second) and 20,000 Hz. Although humans have a hearing range of about 20 Hz to 20 kHz (20,000 Hz), our hearing is most sensitive between the frequencies of 1 kHz (1000 Hz) and 10 kHz (10,000 Hz). So, we can hear some of the clicks, whistles, and ‘boings’ of some dolphins and whales (‘boings’ are made by minke whales), but we have to “visually hear” others that are too low for humans to hear. The vocalizations of some baleen whales are not audible to the human ear, but are detected by the sonobuoy and are visible on the computer with the use of special software. We visually monitor from a range of 10 Hz to 240 Hz, to detect the presence of baleen whales, while listening for higher frequency vocalizations. Signals picked up from the sonobuoys are transmitted to a radio receiver on the ship. All data, including measurements of a vocalization frequency range and duration are recorded on a computer program and also logged in a hand-written journal and rerecorded on an Excel spreadsheet. All data collected will be carefully analyzed in a lab at a later date.

So far on the research cruise, there has been very little cetacean activity observed by visual observers or the scientists conducting acoustic monitoring. These waters have not been widely surveyed for cetaceans, so any data will add to the collective knowledge base of this area. As a scientist, it is important to remember that “the absence of data is data” in understanding the presence/absence and abundance of cetacean species in these deep, low productivity ocean waters.

Personal Log

The Oscar Elton Sette received its sailing orders to leave at 1500 on Monday, April 19, 2010. The generator part we were waiting on finally arrived (by way of Japan!) and we set sail promptly at sailing time. I am finally getting used to using the 24-hour clock!

Sailing orders.

Leaving the dock at Guam.

Sette’s colors flying!

We left Guam with fairly calm seas, but the winds picked up and we were soon rockin’ and rollin’! We had our “Welcome Aboard” meeting, where we learned about ship protocols and safety, as well as getting to know some of the ship’s crew. Of course, a large part of sailing preparation is the “safety drill” and I had my first “close encounter” with a survival suit! The Safety officer, Mike promptly provided me with a survival suit that actually fits much better…the first one could have accommodated two of me!

Karen in survival suit made for 2 Karens.

…and out of the survival suit! Whew!

I was ill prepared for what was to come. With high seas, and no “sea legs” I was struck by seasickness, which sent me right to my bunk to sleep—in fact that was about all I could do! We are fortunate to have a wonderful Doc on board, who provided me with the right meds and advice to be able to recover and feel human again! The greatest comfort I’ve gotten in a long time was to know that “the survival rate for seasickness is 100%!”

Doc Tran who took care of all of the seasick scientists!

My bunk, where I spent most of two days recuperating!

New Term/Phrase/Word of the Day: sonobuoy

Question of the Day: Did you know that sonobuoys were first developed by the U.S. Navy, made to be dropped from aircraft, and designed to locate submarines during WWII?

Something to Think About:

Whales migrate to tropical waters to give birth in winter and spring, and travel to colder, food rich waters for feeding during the summer.

Animals Seen Today:

• Spotted dolphin (Stenella attenuata)

Did you know?

…that scientists take tissue biopsy samples from cetaceans by using a crossbow to shoot a special dart with a metal tip that penetrates the skin and blubber then pops out. The dart has a float and string attached to one end so that it can be retrieved easily with the tissue sample (about the size of a pencil eraser) still inside the tip. Whale research scientists have to be good archers! Don’t worry, the animals rarely notice when they are darted!