NOAA Teacher at Sea
Aboard NOAA Ship Oscar Dyson
July 6 – 25, 2015
Mission: Walleye Pollock Survey
Geographical area of cruise: Gulf of Alaska
Date: July 15, 2015
Weather Data from the Bridge:
Latitude: 56 42.2N
Longitude: 153 46.5W
Sky: Overcast; foggy
Wind Direction: 173 degrees
Wind Speed: 14 knots
Sea wave height: 2ft
Swell wave: 4-5ft
Sea water temp: 12.3C
Dry temperature: 11.5C
Science and Technology Log
In my last post we talked about the Aleutian Wing Trawl (AWT), the mid-water trawling net we use to take samples of pollock. There are two other types of nets we may use during our cruise, although not as frequently as the AWT. Sometimes the echogram shows a large concentration of fish closer to the ocean floor. In this instance, we might use a bottom trawl net, known as the Poly Nor’easter (PNE), to “go fishing”. The process for putting out the net is similar to putting out the AWT, except that it is extended to just above the ocean floor in order to catch fish that are congregated towards the bottom. In our recent bottom trawl, we caught a lot of Pacific Ocean perch, or rockfish, and very few pollock.
The image we use for the bottom trawl
Our net full of rockfish
Rockfish were a little easier to sex than the pollock.
Looks like he got hungry!
These rockfish look cute but have some sharp spines.
3 out of the 4 different types of rockfish we pulled up: POP, yelloweye, and dusky.
Flatfish found in our bottom trawl
An arrowtooth flounder- check out those teeth!
It has been fascinating to see how scientists “do science” out here. Patterns and observations are important skills for scientists, and analyzing patterns and behaviors of fish help scientists to make informed decisions about whether they are seeing pollock, krill, rockfish, or something else entirely on the echogram. For example, acoustically, pollock and rockfish have the same reflectivity (and therefore are difficult to differentiate based solely on acoustics), but their behaviors are different. When we recently put out a bottom trawl net, we anticipated catching mostly rockfish because of the location we were at, and their schooling behavior close to the ocean floor. Rockfish are also usually found lower in the water column than pollock. Our first bottom trawl yielded quite a few rockfish, some jellies, several flatfish, and a few other types of fish. Just as we did with the pollock, we weighed, sexed and measured a sample of rockfish. These fish were a little more difficult to handle as they have sharp spines in several places.
Robert and Derek looking at krill flatfish larvae under the microscope
Counting out a few hundred krill
They’re so tiny!
There is a third type of net we deploy on this survey is called a Methot net. It’s named after Dr. Rick Methot, a famous fisheries modeler. This net has an opening of 5 square meters, and has a finer mesh than the AWT or the PNE at 2x3mm. At the end of the net is a small codend where the sample is taken from. This net is typically used to catch krill and macrozooplankton that would normally escape the larger nets. From the acoustic display, we would anticipate about 100-200 times more than what is actually caught in the net. Back scatter could be one reason for this. Scientists have worked to try and decrease this discrepancy by using strobe lights mounted on the net. The abundance tends to agree better with strobes on the net, with the hypothesis being that the organisms are blinded and don’t realize they’re going into the net.
Meet the Scientists
Kresimir smelling a capelin (smelt)- they smell like cucumbers!
Chris, one of the scientists on board
During one of our shifts, I had the opportunity to interview 2 of the scientists on our night watch team, Kresimir Williams and Chris Bassett. Their enthusiasm and passion for their work is evident in the discussions we have had and the work they are doing. It is great to work with scientists who are so knowledgeable and also patient enough to explain what we are doing here. Let’s meet them!
What is your educational background?
Kresimir: I received my undergraduate degree in marine science from Samford in Birmingham, Alabama. During this time, I spent summers at Dauphin Island. I received my Master’s Degree in fisheries and aquaculture from Auburn (also in Alabama), and finally received my PhD in fisheries from the University of Washington.
Chris: I went to the University of Minnesota for my undergraduate degrees in mechanical engineering and Spanish. I then went on to receive both my Master’s & PhD in mechanical engineering at the University of Washington.
How long have you been working at the AFSC lab in Seattle?
Kresimir: I have been working at the lab for 13 years as a research fisheries biologist.
Chris: I am currently working with both AFSC and the Applied Physics Lab at the University of Washington as a post-doctoral research associate.
What do you most enjoy about your work as a scientist?
Kresimir: I enjoy doing the research, discovering new things, and conducting field experiments.
Chris: The work that I do allows me to learn by playing with big kid toys in beautiful places; for example, the EK80, one of the broadband acoustic scattering systems brought on this ship
What has been a career highlight for you?
Kresimir: The development of the CamTrawl (what we are currently using on our nets here on the Dyson). I have seen this project from development to operationalization.
Chris: Using broadband acoustics systems in a 4 month long lab experiment to detect crude oil spills under sea ice.
What does it mean to you to “do science”?
Kresimir: It means following a set of rules, and discovering things that can be repeated by other people. Remembering that data leads you to the answers rather than using it for something you want to prove. Research generally generates more questions. Finally, it means learning how the little piece of the world you are interested in works.
Chris: It means looking around and seeing what knowledge exists and where we can advance knowledge in that field and how we can do so. It’s understanding that often identifies more new questions than it answers.
What message would you give students who want to pursue a career in (marine) science?
Kresimir: Do your math homework! There are very few biologists out there discovering new things, so you need to bring something else to the table such as coding or geosciences. There is a lot of quantitative modeling and interplay between other sciences such as physics and chemistry.
Chris: Do your math homework! Having skills in a little bit of everything – all of the sciences come into play. You also need good writing skills.
What is your favorite ocean creature?
Kresimir: I love all kinds of fish because I can find something unique about each one of them.
Chris: Bluefin tuna
Thanks for the interview gentlemen!
The Oscar Dyson runs for 10 months out of the year, more than most of the other ships in the NOAA fleet. Many of the people on this ship are here almost year-round, and call the Dyson their home. Having places where they can relax and feel at home is important. Besides up on the bridge or out on the deck, another place to spend some free time is in the lounge. Equipped with beanbag chairs, a large couch, and some comfy chairs, the lounge encourages people to hang out, watch a movie, play video games, or just relax after their shift. We have a large selection of movies, and have access to some of the most recent movies as well. We recently watched Mockingjay, the third movie in the Hunger Games series. It was a good movie, but not as good as the book.
I am really enjoying my time so far on the Oscar Dyson, mostly because I am being challenged to learn new things. We’ve had a bit of downtime the last couple nights, and it has been a good opportunity for me to learn the game of the ship, cribbage. This is a popular game amongst the scientists, and you can typically find some of them playing a quick round in between shifts or as a break from work. I’m by no means great at it yet, but I expect by the end of this trip I’ll be a lot better.
Filleting some rockfish
When I first got on board the Dyson, I remember talking to one of the scientists about filleting fish. I’m not too sure how we got on that subject, but it occurred to me that I had never actually filleted a fish myself. I used to fish as a kid, but we left the cleaning and filleting to my dad (thanks, dad). What could be a better time to learn this skill than on a boat full of experienced fishermen? We ate a rockfish ceviche that Robert, one of the scientists, had made the first night I was on the ship, and it was delicious. When we pulled in our bottom trawl of rockfish, it was the perfect time to learn how to fillet a fish. Rockfish are a bit tricky, as they have several sharp spines covering them. We had to be careful so as not to get stabbed by one of them- it wouldn’t feel very good! I had a busy evening helping to fillet about 14lbs of rockfish. I was by no means quick (our lead fisherman filleted 3 rockfish to my 1), but I had lots of time to practice.
Did you know? Pacific Ocean Perch (POP), or rockfish, were overfished in the 1970’s. Today, Pacific Ocean perch have recovered to the extent that they support a sustainable fishery in Alaska. Read more about the POP.
This POP bears a striking resemblance to the scorpionfish, one of the species we brought up in the SEAMAP Summer Groundfish Survey in the Gulf of Mexico in my TAS trip in 2012. Guess what? These two fish, while living thousands of miles apart, are actually related! They both belong to the family Scorpaenidae.
Pacific Ocean Perch (rockfish)
Scorpionfish we pulled up in a bottom trawl from the Gulf of Mexico (TAS2012)