NOAA Teacher at Sea
Lacee Sherman
Aboard NOAA Ship Oscar Dyson
June 6 – June 28, 2018
Mission: Eastern Bering Sea Pollock Acoustic Trawl Survey
Geographic Area of Cruise: Eastern Bering Sea
Date: June 12, 2018
Weather Data from the Bridge on 6/12/18 at 13:00
Latitude: 56° 15.535 N
Longitude: 161° 17.273 W
Sea Wave Height: 2-3 ft
Wind Speed: 8.8 knots
Wind Direction: 30°
Visibility: 10+ nautical miles
Air Temperature: 7.7° C
Water Temperature: 7.52°C
Sky: Blue with scattered clouds
Science and Technology Log
There are many different types of samples that are taken on NOAA Ship Oscar Dyson. Some of the samples collected on the ship are for the projects of the scientists that are here currently, and other samples are brought back for scientists working on related NOAA projects. The scientists that I am working with are based out of NOAA in Seattle, Washington.
One of the projects that I have been helping with most frequently is processing the trawl samples once they have been collected. When a trawl sample is collected, a large net is lowered off the stern of the ship that will collect the sample of fish (hopefully mostly pollock) and other living things. The net also functions as a vessel to hold scientific instruments that collect other types of information. There is a camera (cam trawl) that is attached to the net and this records video that can be watched through a computer to actually see what is being caught in the net.
Another useful instrument is the FS70, a sonar device that rides above the opening of the trawl net to ping on the fish going into it. Viewed from a screen on the Bridge in real time, this gives the scientists an idea of exactly how many fish are going into the net, so that they can adjust the depth of the net, or change the length of time for the trawl survey. The goal for each trawl sample is to collect at least 300 pollock.
Once the net has been brought in after haulback, the opening at the codend (bottom) of the net is released to allow the sample to be put in a metal tub called the table. The table is capable of holding approximately 1 ton, or 2,000 pounds worth of fish. Sometimes if there is more than can fit on the table, the crew will split the catch in half so that we are only measuring a portion of what was collected. The rest of the fish are stored in another tank on the deck. If we don’t end up with enough pollock on the table, we may need to pick through the other half that was saved on deck until we get enough. Measuring too few of them may not represent the accurate length compositions of the pollock.
On June 11th we collected trawl sample #7. This haul was filled with mainly jellyfish, with pollock and a few herring. The weight of this haul was very close to the amount that the table can hold so it was decided to split the catch. Once we looked at what was put on the table and we realized that it wasn’t going to be enough pollock, Mike and Sarah jumped into the spare tank and pulled out all of the fish (whole haul) so that we would have enough to get as close to that 300 number as possible.
When the fish come into the fish lab, we sort out the different species and put them into separate baskets. Each basket is weighed by species and input into a system called CLAMS (Catch Logging for Acoustic Midwater Surveys). After all of the species have been sorted, a percentage of each species will be measured by length. Another percentage of each species will be measured by length and weight.
From the pollock sample collected, 30 will be randomly picked to have their otoliths removed. The otolith is the ear bone of the fish and it can be used to determine the age of that specific pollock. They have rings, similar to tree rings that can be counted. For information click here.
Personal Log
I have not been shy with anyone onboard about the fact that I would love to see whales if they are around the ship. I feel like this has almost turned into a game at my expense, but I don’t mind. There have been multiple times when there have been “whales” and as soon as I run up the 3 flights of stairs and get to the Bridge, the whales are suddenly gone. I think they are secretly timing me to see how quickly I can run up the stairs! The exercise is good for me anyways.
I’ve finished two books already, which has been really nice. I know that I love to read, but never really take the time anymore because it always seems like there is something else that I should be doing instead. There’s a bookshelf here in the lounge, so I’ll find another to read after I finish the last one that I brought.
I try to spend some time outside every day, and it is so peaceful. I don’t think I’ll ever get tired of waking up and looking at the ocean. I don’t want to take any bit of this experience for granted. I am so grateful that I have this opportunity and I want to take in as much of it as I can. As I get to know more people on the ship I am starting to get to learn more from everyone about exactly what they do and why they chose to make this their profession.
Everyone thinks of scientists, NOAA Corps officers, and engineers as being very serious all of the time, but that couldn’t be further from the truth. Professionalism is incredibly important and is always the focus, but there is also space for fun. Every other day there is a photo competition where a picture is taken somewhere on the ship and you need to find out where it was taken and submit your answer. There are also plastic Easter eggs that keep popping up everywhere filled with positive messages, or candy. The “Oscar Dyson Plan of the Day” sometimes has puzzles to figure out on it as well as important information such as location, meal times, sunrise/sunset times and any other important information.
Did You Know?
There are 6 different species of flatfish found in the Bering Sea. There are 2 species of Flounder, 3 of Sole, and 1 Plaice.
Love it! I am learning so much! Looks like a blast! Love you!