NOAA Teacher at Sea
Onboard NOAA Ship, Oscar Elton Sette
March 12 – March 26, 2012
Mission: Fisheries Study
Geographical area of cruise: American Samoa
Date: March 14, 2012
At Sea: Pago Pago, American Samoa
Science and Technology Log:
My current assignment aboard ship is helping the scientists with the “Nighttime Cobb Trawling” We conduct two trawls in the night, the first one beginning around 9:00 p.m. and the second one at 1:30 a.m.. After each trawl which lasts 2 hours, the nets are brought up and we sort the catch. The scientists are looking for migration patterns and types of sea life in this region. Not much data has been collected in American Samoa.
There are 3 other scientists working on this project.
John Denton, is from the Natural History Museum in New York.
Aimee Hoover works for University of Hawaii.
Sione “Juice” Lam Yuen and Faleselau “House” or “Fale” Tuilagi are from the Fisheries Dept .in American Samoa.
The two trawls exaimine five species of fish:
- Myctophid fish
- non-myctophid fish
- gelatinous zooplankton
During one of the trawls the other night, they think they found a new species of myctophid fish. These fish have photophores which make them glow in the dark. They are anywhere from 4-5 inches to very tiny, 1 inch.
After 4 days on the night shift, I’m getting into the groove. Going to sleep at 6 a.m. and waking up at 1:00 p.m.
It’s crazy. Last night we did 2 trawls for fish. We caught a huge fish, approx 4 feet in diameter, called a Sharptail mola, Masturus lanceolatus or Sunfish. The scientists and crew were able to free him and let him go back into the ocean. Click here to see the exciting video of the release of the Mola: Releasing the Sharptail mola, Masturus lanceolatus/ Sun-fish
When conducting a scientific experiment it is very important to maintain the same procedure or protocol. This allows the scientist to measure only that which he/she is interested in, keeping all constants the same.
Here is the procedure or protocol for each Midwater Cobb Trawl:
1. Secure the TDR and Netminds tracking devices to the trawl net Let out the trawl net, timing for 30 minutes at 350 meters of “wire out.”
2. Ask the bridge and trawl net operator to raise the net line to 100 meters “wire out.”
3. Time the trawling for additional 30 minutes.
4. Once the trawl net has been hauled in:
5. Cut away the TDR and Netminds tracking devices: Their data is read on the computer. Helping scientists determine temperature, depth for each trawl.
6. Working together, scientist and crew members collect the specimens caught is the Cobb net.
7. The fish collected are taken to the wet lab and strained into a net that is in turn poured into examining trays.
8. Scientists then collect data including: weight (volume & mass), length (centimeters) , and count the number of each species recording the
minimum and maximum lengths.
9. The scientists preserve each group of fish in ethanol/ ethyl alcohol which eases transportation and preserves the fish for further study back in the lab.
I’ve switched to working the night shift, tonight being the third night. It’s getting a little easier, although we all still get punchy around 3-4 a.m. I am scheduled to work nights until next Monday. We will continue counting the fish, setting the trawl nets out, imputing the data, preserving the fish. All very interesting work.
Sharptail mola, Masturus lanceolatus fish
Moorish Idol fish