Jennifer Fry: March 14, 2012, “Pi Day” 3.14, Oscar Elton Sette

NOAA Teacher at Sea
Jennifer Fry
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:

  1. Myctophid fish
  2.  non-myctophid fish
  3.  crustaceans
  4.  gelatinous zooplankton
  5.  cephalopods

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.

Myctophids are among the most numerous fish in the sea. They have specific light producing organs called photophores.

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

During tonight's Cobb trawl a sharp-tailed mola was caught in the net. The crew and scientists aided in freeing the fish allowing him to swim away. Mola can reach 100 years old.

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.

Personal Log:

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.

Animals Seen:

Sharptail mola, Masturus lanceolatus fish

Moorish Idol fish

Two Moorish Idol fish were caught in the Cobb Trawl net. Their colors were brilliant including their unique dorsal filament.

Author

One Reply to “Jennifer Fry: March 14, 2012, “Pi Day” 3.14, Oscar Elton Sette”

  1. The sunfish looks very interesting. Makes me really consider all that we don’t know about what’s happening under those seas.

Leave a Reply