Jennifer Fry: March 17, 2012, Oscar Elton Sette

These crustaceans are sorting into a tray then measured for length (mm), volume (ml), and mass (g).

Mission: Fisheries Study
Geographical area of cruise: American Samoa
Date: March 17, 2012

Pago Pago, American Samoa

Cobb Trawl Day 6

Location: Wet Lab

Poetry into the Wee Hours of the Night

Here’s the data from Cobb Trawl Day: 6.1                                                                                        Total mass of trawl: 490 g

Name of fish: Numbers Count Volume (milliliters) Mass (grams)
Myctophids 124 140 150
Non-Myctophids 58 80 75
Crustaceans 14 negl negl
Cephalopods: 10 30 30
Gelatinous zooplankton 59 104 100
Misc. zooplankton n/a 60 97

Animals seen:

Lizard fish

Light fish

Mantis shrimp

Ctenophore/ comb jellies

Stomatopod

This coronet fish, in its larval form, was found in the Cobb trawl net.
The snipe eel is one the longer fish we caught measuring 150 mm.
The snipe eel mouth is shown close-up.
Scientists sort the nightly catch after each Cobb trawl. Trays are used to divide into each catagory: myctophids, non-myctophids, crustaceans, cephalopods, gelatinous zooplankton, and misc. zooplankton

Cob Trawl Day 6.2 :Total Mass 1035 g

Name of fish: Numbers Count Volume (milliliters) Mass (grams)
Myctophids 385 300 232
Non-Myctophids 51 60 70
Crustaceans 17 6 7
Cephalopods: 32 26 55
Gelatinous zooplankton 122 400 405
Misc. zooplankton n/a 240 225

Animals seen:

Trumpet / coronet fish

Snip eel

Salps

Balloon squid

Fulmar bird

This fulmer bird landed on the deck of the ship during nighttime Cobb net trawling.

Poetry into the Wee Hours of the Night: A collaborative effort:

“The Cobb Trawl Net” / With my week nearly over working  on the Cobb Trawl Net, I asked the scientists to join me in writing some scientific poetry about the operation.   The Cobb Trawl Net operation is overseen by John Denton and Aimee Hoover. The net is brought out of the water twice during the wee hours of the night, using a large noisy winch which certainly disturbs the slumber of those light-sleepers on the ship.  Coinciding with the Cobb Trawl Net activities are  nightly Plankton Tows.

 “I Wander Lonely as a Plankton” and “Plankton Mother”  honor the various types of plankton and microplastics that Emily Norton and Louise Giuseffi are studying.  We have been towing in different regions of American Samoan seas.  One area is called 2% Bank.  The other banks are called Northwest Bank and  Southbank.

“Myctohpids” / Since most of the bio-mass of the ocean is taken up by the little myctohpid fish, they are represented with an acrostic poem.  The poems show a passion for science and the research being conducted here in American Samoa.  I truly thank these scientists, John, Aimee, Emily, and Louise for their teachings, patience, and sheer enthusiasm for their scientific projects.

The Cobb Trawl Net

inspired by” The Fog” by Carl Sandberg

The trawl net comes in on thundering howl

The great black maw

Grinding and snarling brings in its folded catch,

The ocean’s toothy offering from the liquid, teeming abyss.

I Wander Lonely as a Plankton

Inspired by “I Wander Lonely as a Cloud” by William Wordsworth

I wander lonely as a copepod

That floats high and low in the sapphire blue water column ofAmerican Samoa

When all at once I saw a school

A host of dog tooth tuna

Along the 2% Bank

Beneath the NOAA ship OscarElton Sette

Thunniform undulation and escaping through the gently rolling waves.

Plankton Mother

 

Meticulously, she guards her catch

A treasure trove of tiny beasts

Carefully each dish is filled for observation.

Peering through the powerful microscope the

Blinking, pulsing Cephalopods, the cobalt Copepods, and spiral, conical Pteropods

So fragile to the touch

Tweezers carefully coax each delicate specimen into position

Checking for morphological traits

Does it have…

…Mysterious dark organ on its tiny body?

…Pointy sword-like structure on its rostrum?

The newly found charge is preserved in a viscous solution

Our link to plankton’s DNA

 transcriptome: all our DNA used to make proteins,

the building blocks of life

life’s basic units for construction

Myctophids

 

 Multitudes of  photophores, cup-shaped light emitting organs of epidermal origin.  Many many  millions of  blinking dots

Yellow irises look  with dreamy eyes like a  glazed over donut.

Clues to many different species found in the mesopelagic layer of the deep, ebony ocean.

The ctenoid scales possessing sharp, spiky spines

Out of the obsidian shoots the silver sprites, the beautiful slender fish

Prickly long-tailed myctophids with their stern-chasers, supracaudal/infracaudal luminous organs

Hungry for krill, small crustaceans, copepods and other planktonic creatures

Iridescent

Densly packed balls of gleaming, pulsing Actinopterygians A.K.A.  Actinops

Schooling,  synchronistic swimmers, tiny voices of light circumgloabally distributed around the world, cosmopolites.

A collaboration by:

John Denton, Emily Norton, Aimee Hoover,  Megan Duncan, Louise Guiseffi, and Jennifer Fry

Jennifer Fry: March 23, 2012 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 23, 2012

Pictured here is a copepod (right) and a jelly (left) found in the plankton net.
Copepod comprise approximately 85 % of the plankton population
Copepod comprise approximately 85 % of the plankton population.
These copepods images taken with a high-powered microscope with an internal camera.

 Plankton Net Operation

11:00 p.m.

Learning how to work with the plankton net was so interesting.  It required careful, meticulous, and orderly work.  Emily Norton, University of Hawaii at Manoa, Biological Oceanography, is conducting daytime and nighttime tows targeting plankton.  She’s particularly interested in collecting and studying copepods, a type of small crustacean which comprise ~80-90% of the plankton. Plankton is a name for a variety of plants and animals that live in the water column and are found throughout the world’s oceans.  Plankton are important because they are an integral part of the food chain, and they can help scientists better understand currents and transport in the oceans.  Helping with the plankton tow is Megan Duncan, oceanography participant, Joint Institute for Marine and Atmospheric Research at the University of Hawaii.  Together we deployed the net starting around 11:00 p.m.  Due to migration patterns known as diel vertical migration, plankton can be collected more easily at night.

  1. The net consists of a 1 meter metal ring with a fine mesh (200 um) net attached to collect the plankton.
  2.   At the end of the long, conical net is a collection filter tube or “codend.”  This is the final collection point for all of the specimens funneled into the mouth of the net.
  3.   The flowmeter is then connected across the diameter of the metal ring, which measures the amount of water flowing past it.
  4. With a crane operator’s help the net is lowered into the sea with 230 feet wire out which calculates to approximately 200 feet deep.  This is called an “oblique tow” method.
  5. The net remains in the water for 30 minutes.
  6. Once brought to the surface, the net is rinsed with sea water multiple times to ensure all of the plankton are completely  flushed down  into the cod end.
  7. The next step is filtering the plankton-rich seawater through a very fine sieve.
  8. The plankton are either observed under a microscope or immediately preserved using an ethanol solution, 95% ethanol 5% water.
  9. Labels are then placed inside the jar written in pencil on waterproof paper, and outside the jar using indelible marker.
  10. The plankton will be processed at a later date in the lab for quantitative analysis.
  11. In the lab, scientists study the plankton further, making observations and studying the DNA, Deoxyribonucleic Acid using PCR, Polymerase Chain Reaction, and sequencing.  Similarities and differences (i.e. mutations) in the DNA sequences are used by scientists to determine how closely related populations of copepods are.  This helps scientists infer how currents affect connectivity in the ocean.

Animals seen:

Copepods

Pteropods

Baby giant squid

juvenile fish, various species

Euphausiid

 Q:What fish have you had the most interest in and why?

A: The most common fish caught in the net is the lanternfish or myctohid.  They represent nearly 85%  of the ocean’s biomass.  One interesting feature is their photophores which produce light that emit from their bodies.

The myctophid pictured on the top is seen with its scales, compared to the bottom that shows them rubbed off due to being in the Cobb trawl net.

This tray of myctophids or lantern fish make up nearly 85% of the ocean’s biomass. They were the most common fish in our night Cobb Trawl nets.

Q: Have you gone scuba diving?

A:  No, I didn’t do any S.C.U.B.A. (self-contained underwater breathing apparatus) diving on this trip.  There are NOAA ships that focus on research that require diving as their method of collecting data.  We visited the NOAA ship Hi’ialakai that researches the coral reef biome in the American Samoa waters.

The NOAA ship Hi’ialakai conducts S.C.U.B.A. operations researching the coral reefs of American Samoa.