Maureen Anderson: Data and Measurement, July 31, 2011 (Post #4)

NOAA Teacher at Sea
Maureen Anderson

Aboard NOAA Ship Oregon II (NOAA Ship Tracker)
July 25 — August 9, 2011

Mission: Shark Longline Survey
Geographical Area: Southern Atlantic/Gulf of Mexico
Date: Sunday, July 31, 2011

Weather Data from the Bridge
Latitude:  30.39 N
Longitude: -080.41 W
Wind Speed: 13.67 kts
Surface Water Temperature: 29.50 C
Air Temperature:  29.10 C
Relative Humidity: 78 %
Barometric Pressure:  1016.43 mb
Water Depth: 37.10 m

Science and Technology Log

A part of any good experiment or survey is the careful collection of data. We know that without a good data collection plan, our results may have error or be open to wide interpretation. The shark longline survey has been going on for the past 17 years in order to understand the abundance of shark species in this area.  It has standard procedures and protocols that we must follow so that each survey is consistent.  Hmm…that sounds similar to what we do in science class!

Every time we reach a “station” (a pre-designated spot) our team collects data on the characteristics of that area. One piece of technology we use to do this is called a CTD (which stands for conductivity, temperature, and depth). This instrument is placed overboard with the help of a winch and takes measurements for several minutes. Conductivity tells us information about the salinity (amount of salt) of the water. The device also reads the temperature, depth, levels of  chlorophyll, dissolved oxygen, and can give us water samples. This is important because every time we change stations, we want to know about the conditions of that area. The data from the CTD is then sent electronically to a data room and graphed.


Here is the CTD which measures conductivity, temperature, and depth

We also collect data on the color of the ocean water, the wave height, and the percentage of cloud cover. This last one is a bit tricky because it is so subjective.

It is also important to collect data consistently. There are two shifts aboard the boat – the day shift (which I am on) and the night shift. Each shift is 12 hours long. We collect data even in the middle of the night. What do you think would happen if we only collected data on sharks during the day time?

CTD graph

This is a graph of data from the CTD. The temperature is in blue, salinity is red, and depth is on the left vertical axis.

There are several measurement tools we use. The measuring board allows us to place a small shark on the board and read its length in millimeters. We take two readings – one for the length from the snout to the fork where the tail splits, the other for the entire length of the shark from end to end. The spring scale is used to measure the shark’s weight in kilograms. If the shark is too big for either of the above tools, we will take measurements in the cradle. We use a flexible tape measure for length, and record weight through a scale on the cradle. We know the cradle’s weight, so all we have to do is record the total weight of the cradle with the shark in it and subtract (see kids, math in the real world!)

cloud cover

Can you guess the percentage of cloud cover here?

We tag some sharks with a Roto clip and/or an identification marker.  All of the data is written down on a clipboard and then entered into a database.  Pictures are also taken with a camera so that we can photo-document the catch.  Each picture is renamed with the corresponding ID number of the tag so that we have a database of images.

Personal Log

I mentioned earlier that we have satellite TV access on the  boat.  Actually there are three – one in the lounge and two in the galley.  Funny enough, we have the perfect program to watch this week on the Discovery channel…happy Shark Week everyone!  Yesterday, we had to postpone doing our longline survey at one station due to a distress call from a small boat that was 10 miles away.

spring scale

In this photo, I'm using a spring scale to weigh a sharpnose shark.

The crew aboard our ship got ready to perform a search and recovery operation by getting the Zodiac rescue boat ready.  But as it turned out, another vessel was able to aid them faster, and we resumed our work.  I was amazed to see the crew jump into action and be ready so fast.

Species Seen Today
Atlantic Sharpnose Shark
Sandbar Shark
Mutton Snapper
Tiger Shark

cradle with sandbar shark

This sandbar shark is too large to bring on deck. It is measured in the cradle.

Rescue boat

This is the Zodiac rescue boat ready for deployment.

fin tips

These fin tip samples will help with shark identification.

Tools to Tag

This roto tag (small yellow clip) and identification marker are used to tag the shark.

Tiger shark with Roto tag

This very small, young Tiger shark now has a Roto tag on its fin

half sharpnose

Something was hungry for the other half of this Atlantic sharpnose.

Jennifer Richards, September 11, 2001

NOAA Teacher at Sea
Jennifer Richards
Onboard NOAA Ship Ronald H. Brown
September 5 – October 6, 2001

Mission: Eastern Pacific Investigation of Climate Processes
Geographical Area: Eastern Pacific
Date: September 11, 2001

Latitude: 12º 06.3 N
Longitude: 95º 49.7 W
Temperature: 26.5 º C
Seas: Sea wave height: 2-3 feet
Swell wave height: 4-5 feet
Visibility: 10 miles
Cloud cover: 6/8
Water Temp: 29.7 ºC

Special note: The storm we hit yesterday is now classified and named “Hurricane Ivo”

Research Objective for the day: Install sensors on the buoy at 10N, 95W. Download data from the buoy into the ship’s system for analysis.

Science Log

Today is the first day that official operations take place. We reached the first buoy at 10N, 95W around 4pm, and the zodiac sent several people out to it for maintenance. Divers installed sensors on the under-water portion. They also downloaded the data from the buoy for analysis.

There are lots of buoys in the ocean. Mr. John Stanley (who I will introduce you to later in the week) is in charge of the buoy work on this cruise. He’s installing some, repairing some, and doing general maintenance.

One neat thing about the buoys is that the anchors that keep them in place develop their own ecosystem. All sorts of stuff grows on the anchor line, and stuff that eats the stuff on the line hangs out in the area. And the stuff that eats the stuff that grows on the line is also there. You get the picture. This means that whenever we reach buoys, people on the ship start reaching for their fishing gear. Although we didn’t see any today, I’ve been told that there are often white-tip sharks in the area, and things can get pretty exciting (especially with a diver in the area). Today Pat, one of the crew, caught a pretty good-sized yellow-tail tuna. It was cool, until it started bleeding all over the deck. That’s when I decided I should go look at something else.

Travel Log

This has been a quiet day. Most people on the ship are in some kind of shock after hearing of the terrorist activities on the east coast. I know I speak for everyone on board when I say that all of our thoughts are with the thousands and millions of people who have been affected by the attacks on the World Trade Center and the Pentagon. I tried for hours to reach my family in the Washington, D.C. area, but I was never able to get a connection. Inmarsat-M phone calls must first connect with a satellite operator (challenge #1), and then connect with land (challenge #2). To those of you reading this who have family or friends on the ship, please remember that in an event like this, e-mail is a reliable way to communicate. Our computer guy, Larry, connects with the satellite twice a day – 10:00 am and 6:00 pm. We are now in Mountain Standard Time, one hour later than when we started, 6 hours off of Greenwich Mean Time (GMT).

Today marks the one-week anniversary of when I arrived on the ship. In some ways, it feels like it went quickly, but at the same time, I feel like I’ve been here forever. One of my students, Melissa, asked if it was hard to be away from home. To be honest, I try not to think about it. I miss my husband, Rob, and we email regularly, but I try not to remind myself that I won’t be home for another month. Certainly on a tragic day like this, all I can think about is how far away from home I am.

Question of the day: Why is cloud cover measured in 8ths (example 1/8, 7/8, etc)?

Photo Descriptions: Today’s pictures include the following: the zodiac at the buoy, fishing off the stern of the boat, Pat’s fish, a close-up of a buoy on the ship (will be installed later on the trip), and Captain Dreves keeping a close eye on the buoy operations.

Until tomorrow,