Emily Whalen: Trawling in Cape Cod Bay, April 29, 2015

NOAA Teacher at Sea
Emily Whalen
Aboard NOAA Ship Henry B. Bigelow
April 27 – May 10, 2015

Mission: Spring Bottom Trawl Survey, Leg IV
Geographical Area of Cruise: Gulf of Maine

Date: April 29, 2015

Weather Data:
GPS location:  4251.770’N, 07043.695’W
Sky condition:  Cloudy
Wind: 10 kts NNW
Wave height: 1-2 feet
Water temperature:  6.2○ C
Air temperature:  8.1○ C

Science and Technology Log:

On board the Henry B. Bigelow we are working to complete the fourth and final leg of the spring bottom trawl survey. Since 1948, NOAA has sent ships along the east coast from Cape Hatteras to the Scotian Shelf to catch, identify, measure and collect the fish and invertebrates from the sea floor. Scientists and fishermen use this data to assess the health of the ocean and make management decisions about fish stocks.

What do you recognize on this chart?  Do you know where Derry, NH is on the map?

This is the area that we will be trawling. Each blue circle represents one of the sites that we will sample. We are covering a LOT of ground! Image courtesy of NOAA.

Today I am going to give you a rundown of the small role that I play in this process. I am on the noon to midnight watch with a crew of six other scientists, which means that we are responsible for processing everything caught in the giant trawl net on board during those hours. During the first three legs of the survey, the Bigelow has sampled over 300 sites. We are working to finish the survey by completing the remaining sites, which are scattered throughout Cape Cod Bay and the Gulf of Maine.  The data collected on this trip will be added to data from similar trips that NOAA has taken each spring for almost 60 years.  These huge sets of data allow scientists to track species that are dwindling, recovering, thriving or shifting habitats.

The CTD ready to deploy.

The CTD ready to deploy.

At each sampling station, the ship first drops a man-sized piece of equipment called a CTD to the sea floor. The CTD measures conductivity, temperature and depth, hence its name.  Using the conductivity measurement, the CTD software also calculates salinity, which is the amount of dissolved salt in the water.  It also has light sensors that are used to measure how much light is penetrating through the water.

While the CTD is in the water,  the deck crew prepares the trawl net and streams it from the back of the ship.  The net is towed by a set of hydraulic winches that are controlled by a sophisticated autotrawl system.  The system senses the tension on each trawl warp and will pay out or reel in cable to ensure that the net is fishing properly.

Once deployed, the net sinks to the bottom and the ship tows it for twenty minutes, which is a little more than one nautical mile. The mouth of the net is rectangular so that it can open up wide and catch the most fish.  The bottom edge of the mouth has something called a rockhopper sweep on it, which is made of a series of heavy disks that roll along the rocky bottom instead of getting hung up or tangled.  The top edge of the net has floats along it to hold it wide open.   There are sensors positioned throughout the net that send data back to the ship about the shape of the net’s mouth, the water temperature on the bottom, the amount of contact with the bottom, the speed of water through the net and the direction that the water is flowing through the net.  It is important that each tow is standardized like this so that the fish populations in the sample areas aren’t misrepresented by the catch.   For example, if the net was twisted or didn’t open properly, the catch might be very small, even in an area that is teaming with fish.

Do you think this is what trawl nets looked like in 1948?

This is what the net looks like when it is coming back on board. The deck hands are guiding the trawl warps onto the big black spools. The whole process is powered by two hydraulic winches.

After twenty minutes, the net is hauled back onto the boat using heavy-duty winches.  The science crew changes into brightly colored foul weather gear and heads to the wet lab, where we wait to see what we’ve caught in the net. The watch chief turns the music up and everyone goes to their station along a conveyor belt the transports the fish from outside on the deck to inside the lab. We sort the catch by species into baskets and buckets, working at a slow, comfortable pace when the catch is small, or at a rapid fire, breakneck speed when the catch is large.

If you guessed 'sponges', then you are correct!

This is the conveyor belt that transports the catch from the deck into the wetlab. The crew works to sort things into buckets. Do you know what these chunky yellow blobs that we caught this time are?

After that, the species and weight of each container is recorded into the Fisheries Scientific Computing System (FSCS), which is an amazing software system that allows our team of seven people to collect an enormous amount of data very quickly. Then we work in teams of two to process each fish at work stations using a barcode scanner, magnetic lengthing board, digital scale, fillet knives, tweezers, two touch screen monitors, a freshwater hose, scannable stickers, envelopes, baggies, jars and finally a conveyor belt that leads to a chute that returns the catch back to the ocean.  To picture what this looks like, imagine a grocery store checkout line crossed with an arcade crossed with a water park crossed with an operating room.  Add in some music playing from an ipod and it’s a pretty raucous scene!

The data that we collect for each fish varies.  At a bare minimum, we will measure the length of the fish, which is electronically transmitted into FSCS.  For some fish, we also record the weight, sex and stage of maturity.  This also often includes taking tissue samples and packaging them up so that they can be studied back at the lab.  Fortunately, for each fish, the FSCS screen automatically prompts us about which measurements need to be taken and samples need to be kept.  For some fish, we cut out and label a small piece of gonad or some scales.  We collect the otoliths, or ear bones from many fish.

It does not look this neat and tidy when we are working!

These are the work stations in the wet lab. The cutters stand on the left processing the fish, and the recorders stand on the right.These bones can be used to determine the age of each fish because they are made of rings of calcium carbonate that accumulate over time.

Most of the samples will got back to the Northeast Fisheries Science Center where they will be processed by NOAA scientists.  Some of them will go to other scientists from universities and other labs who have requested special sampling from the Bigelow.  It’s like we are working on a dozen different research projects all at once!




Something to Think About:

Below are two pictures that I took from the flying bridge as we departed from the Coast Guard Station in Boston. They were taken just moments apart from each other. Why do you think that the area in the first picture has been built up with beautiful skyscrapers while the area in the second picture is filled with shipping containers and industry? Which area do you think is more important to the city? Post your thoughts in the comment section below.

Rows of shipping containers. What do you think is inside them?

Downtown Boston.  Just a mile from the shipping containers.  Why do you think this area is so different from the previous picture?

Downtown Boston. Just a mile from the shipping containers. Why do you think this area is so different from the previous picture?










Personal Log

Believe it or not, I actually feel very relaxed on board the Bigelow!  The food is excellent, my stateroom is comfortable and all I have to do is follow the instructions of the crew and the FSCS.  The internet is fast enough to occasionally check my email, but not fast enough to stream music or obsessively read articles I find on Twitter.  The gentle rocking of the boat is relaxing, and there is a constant supply of coffee and yogurt.  I have already read one whole book (Paper Towns by John Greene) and later tonight I will go to the onboard library and choose another.  That said, I do miss my family and my dog and I’m sure that in a few days I will start to miss my students too!

If the description above doesn’t make you want to consider volunteering on a NOAA cruise, maybe the radical outfits will.  On the left, you can see me trying on my Mustang Suit, which is designed to keep me safe in the unlikely event that the ship sinks.  On the right, you can see me in my stylish yellow foul weather pants.  They look even better when they are covered in sparkling fish scales!

Seriously, they keep me totally dry!

Banana Yellow Pants: SO 2015! Photo taken by fellow volunteer Megan Plourde.

Seriously, do I look awesome, or what?

This is a Mustang Suit. If you owned one of these, where would you most like to wear it? Photo taken by IT Specialist Heidi Marotta.

That’s it for now!  What topics would you like to hear more about?  If you post your questions in the comment section below, I will try to answer them in my next blog post.

17 responses to “Emily Whalen: Trawling in Cape Cod Bay, April 29, 2015

  1. Wow! Are the yellow things a species of sponge? What is the most odd creature you have caught so far?

  2. Thanks for the terrific update! Both the Boston areas you photographed are equally important and critical to the social, economic and strategic vitality of the city, it’s citizens, the region and the country. Question: How would you describe the overall health and welfare of the waters and the species you are sampling? Love the fashion statements! Stay safe. Cooper is doing just great! Hugs & Kisses, DaDa

  3. Lots of information about your life on board the Bigelow. I enjoyed your pictures and descriptions of the important work you are all doing (and your cool clothes)! I hope you all find that our ocean is healthy and our species populations are thriving.

  4. I think, by the very nature of your taking this trip, and your multitude of other stories, you are, in your own way, Margo Roth Spiegelman.

    Also, please share what those yellow things are.

    What do seven scientists stuck together on a boat talk about? On day one? On day seven? On day twelve?

  5. 1. that’s Why my classroom Is such a Mess…it is A trail of Clues.
    2. The yellow things are sponges…believe it or not they are actually alive!
    3. We have talked alot about fish superlatives: best eyes, nicest fins, best personality, most likely to succeed, class clown. Stay tuned for updates in my blog posts. We have also been talking about ‘regionalisms’ like poutine vs. disco fries and sprinkles vs. jimmies. Can you think of any for our area? Also any tips for what you think would be interesting to talk about? I still have 8 days out here….

  6. The one thing that I am learning out here is that every fish and every sample site is just one piece of a huge puzzle. I can say that we have seen lots of really cool fish and lots of healthy fish. As to the overall health of the waters? That’s above my pay grade to say! There was an interesting article in the Dec. 2013 Yankee magazine that you might want to check out on that topic! Hugs to Cooper!

  7. Hi Molly, You are right–they are sponges! And they are not at all square, so….

    We have seen some pretty weird things. Last night we got quite a few octopi which were pretty awesome. I took some pictures so I will be sure to show them to you when I get back!

  8. Hi Emily! What an amazing adventure! You say that the boat is a gentle rocking. Have you had any sea sickness? I would imagine that would be my biggest problem. As far as regionalism, how about “wicked awesome” or as we say, “wickid awesome”. I am interested to hear your thoughts about the health of our oceans. It is something I worry and wonder about. Looking forward to hearing more from you.

  9. Hi Patty,
    The first morning out, we hit some rough seas and I felt a little queasy, but since then the weather has been great. Check out my next post for some thoughts about the state of ocean–it should be published later today or early tomorrow!


  10. Hi Ms. Whalen,
    It looks like a really fun trip. You say that they have been doing this voyage since 1948. Is the Bigelow the same boat they have used for the last 67 years?

  11. A brief list of regionalisms said in New Hampshire (generated by (some of) the NCS staff):
    soda vs. pop/coke/fizzy water
    roundabout/rotary/traffic circle
    water fountain/bubbler

    Other conversation topics (from this morning):
    Should Rachel wear her shorts on the outside of her pants?
    Tying shoes
    Visual models for teaching a group of super uncomfortable kids about sex
    Why is your cabinet so far from the table?

  12. A current hot topic among my watch is this: which movie is more iconic, Back to the Future or Harry Potter? Care to weigh in?

  13. Ms. Whalen,

    That is a tough question, but I would have to say that Back To The Future is more iconic. I personally like Back To The Future much better than Harry Potter.


  14. Hi Jake,
    No, the Bigelow was built in 2007. Prior to that, there were several other ships used. The Bigelow has modern technology that makes data collection easier than ever. It is also designed to be energy efficient. Check out my next blog post about how electricity is used to power the propeller.

  15. Wow, this ship holds some pretty awesome equipment for work out in sea, and those are some pretty weird looking fish, they look a little like yellow clay.

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