Germaine Thomas: Big Boats and Little Boats and How They Fish Differently, August 10, 2023

NOAA Teacher at Sea

Germaine Thomas (she/her)

Aboard NOAA Ship Oscar Dyson

August 7 – August 21, 2023

Mission: Acoustic Trawl Survey (Leg 3 of 3)
Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska
Date: Friday, August 10, 2023

Weather Data
Lat 59.47 N, Lon 149.36 W
Sky condition: Cloudy and rain
Wind Speed: 23.73 knots
Wind Direction: 72.22°
Air Temp: 14.47 °C

Science Log

Comparing Set Netting to Trawling

There are many different ways to catch fish. I am comparing set netting, in a little boat, a 24 ft. skiff to trawling on NOAA Ship Oscar Dyson, a big boat which is 208 ft. This is a little bit like comparing apples to oranges; set netting and trawling are different gear types used to catch fish very differently. Set netting targets mostly salmon, while trawling in Alaska targets mostly pollock. Both of these methods of fishing can be used by scientists to collect samples and to catch fish commercially to sell in global markets.

Set Netting:

I am a commercial set netter, which uses a gill net, specifically designed to catch salmon by the gills. Salmon will swim along the shoreline. Set netters place their nets perpendicular to the shore so salmon have to swim around the nets or try to swim through them. When they try to swim through the fish get caught by the gills. Watch the video below on how I pull the net in using a hydraulic roller and pick fish out.

Pulling in the net and picking a Sockeye salmon

[Transcript: Yup, here I am, picking a… Sockeye salmon! Yup, here it is, a beautiful, lovely, amazing Sockeye salmon that I picked. This is what I do in the summer! Yeah!]

When you watch the video you will see the net is a light color that matches the water. Again, salmon do not see the net and try to swim through it and then they are caught. At the end of the video I place the fish in a brailer bag filled with ice and sea water to keep the fish cool. The better the fish are cared for, the better the product that goes to market.


Unlike set netting, which is done on a small skiff with just a few people, trawling is done on a large boat with a big crew. The Oscar Dyson has the ability to use echo-sounders to find out where fish are, and then they can lower a trawl net into the water specifically sampling at that depth for fish. A trawl net is like a big bag with are large opening that funnels fish into it.

The Scientists on NOAA Ship Oscar Dyson use a much smaller net than a commercial trawler does to catch fish. They compare what they see on their echo-sounders to what is caught in their net. They use this information to get a general idea of what kind of fish are present in a specific part of the ocean they are sampling. This helps scientists provide accurate information to both the federal and state government to help manage fisheries and keep intact healthy populations of fish.

A commercial trawler will try to catch a specific kind of fish, their target species. If they catch fish other than their target species this is known as bycatch. Large commercial trawlers can have nets up to 50 meters in length, so they can catch a lot of fish. They can only keep and sell their target species. The fish that the Oscar Dyson catches cannot be sold or eaten, but the data the collection provides scientists a great deal about what kind of fish, approximately how many, and at what stages of reproductive development, are located in specific areas of the ocean.

How trawling can impact salmon fisheries like set netting:

Knowing what is happening in a different part of the ocean is very important to other fisheries. Salmon initially develop in fresh water lakes or rivers and then migrate to the ocean. They spend most of their adult life migrating large distances in the ocean, and they depend on food that is present out where the trawlers are fishing. They also may be caught by trawlers as bycatch.

Below is a short sped up video of crew members retrieving a trawl net.

Crewmembers aboard NOAA Ship Oscar Dyson retrieve a trawl net. [No audible dialogue.]

In Alaska there is a bit of controversy over one gear type taking away fish from other gear types. Specifically there is concern about commercial trawling, picking up non-target species like salmon from local coastal fisheries and subsistence users. A lot of the answers may exist in the data that the science team is collecting.

Personal Log

At the beginning of the blog in the weather report you will notice that the wind speed is pretty high at 23.72 knots. A gale is heading towards our area in the Gulf of Alaska. We are finishing a transect line and then heading into a protected bay in the Kenai Peninsula to wait out the weather. While the ship is protected, the science team will work on recalibrating the echo-sounders below the ship. The science team has been experiencing a bit of unexplained noise in one of their lower frequencies. Hopefully, the opportunity to do this calibration will help.

Crew Member in the Spotlight

The Oscar Dyson has a science team and a crew that work together to collect the data for the acoustic trawl sampling and run the ship. Working for NOAA can provide exciting opportunities for young people to experience life on the ocean. When you are on board the ship, you have free lodging and food, which on this leg of the cruise is quite excellent, so you can save money while on board. So far everyone I met enjoys their job and is willing to let me ask them questions about how they got here.

Dee gives a slight smile for a portrait photo. She is wearing a black NOAA Ship Oscar Dyson hoodie, with the hood pulled up over a gray NOAA logo beanie (which also has the hull number of Oscar Dyson, R 224). She stands in front of a framed watercolor of the ship superimposed on a nautical chart of the waters around Kodiak Island. The frame is surrounded by gold garland.
Dee with a picture of the Oscar Dyson in the background

Meet Elvricka “Dee” Daniels from Jacksonville, Florida. She has been on NOAA Ship Oscar Dyson for about 2 months. She was originally temping for an agency in Florida when a friend told her about a subcontractor for NOAA, Keystone. She is currently working as a deckhand for the contractor Keystone.

What does she enjoy aboard the ship?

“Fishing! What kind of different fish come in the trawl net. There is always something different every time we fish.”

She also really likes being on whale watch on the bridge. The science team cannot set out the net if there are whales in the area, so there is always a crew member looking for whales.

As a high school teacher, I like to ask people what their school experience was like. Everyone has a different experience in high school some good some, perhaps not so good, but many go on be successful adults. What was high school like for Dee?

“It was good at first and then it got bad. I made poor choices that impacted my life, I had to go to summer school to make up for missed school. Doing well in school is very important to my family.”

So now here she is out in the Gulf of Alaska helping science happen and impacting others by what she does.

Leave a Reply

%d bloggers like this: