Story Miller, July 24, 2010

NOAA Teacher at Sea: Story Miller
NOAA Ship: Oscar Dyson

Mission: Summer Pollock III
Geographical Area: Bering Sea
Date: July 24, 2010
View from the Deck
View from the Deck

Time: 1837 ADT
Latitude: 62°11N
Wind: 15.1 knots (approx. 17.4 mph)
Direction: 156° (SW)
Sea Temperature: 8.3°C (approx. 47°F)
Air Temperature: 7.4°C (approx. 45.3°F)
Barometric Pressure (mb): 1007
Wave Swells: 4 – 5 feet
Wave Height: 1 – 2 feet
Combined: 5 – 6 feet

Scientific Log:
Today started out with the launching of another CTD (Conductivity, Temperature, Depth) and XBT to measure the salinity and temperature of the ocean. On average we typically deploy a little more than one per day, depending on whether we are wanting to hit key locations. Today when we launched two and contrasted locations where there were pollock to locations where there weren’t so we could better analyze how sea temperature affects where the pollock prefer to hang out.

Survey Tech, Robert Spina, taking samples from the CTD

We attempted to launch the Cam-Trawl this morning but as is typical with new equipment, we encountered some problems once it was in the water. And as my students have learned, sometimes it’s necessary to make modifications and try the science experiment again! Even the pro’s must go through the Scientific Method multiple times before they can publish their findings!

Ovaries of a female Walleye Pollock

At approximately 1030 we deployed the AWT and went fishing for more pollock. This time we were able to gather a variety of different ages between the years 1-3. Once the fish are dumped from the codend, they are placed on a type of conveyor belt that allows us to do a preliminary sort through the fish. For example, jellyfish are commonly caught in the net and so we place them in a separate bucket to measure later. Sometimes we accidently catch other fish in the net, this is called bycatch, and they too need to be separated. At the end of the conveyor belt another person weighs baskets of fish and records the weights in the computer. Afterward, we take a random sample of about 400 fish and sex them. This sample is used to determine how many fish of each size are in the sample.  Unfortunately we do not have a way to identify the sex of the fish without having to cut into them to see. In addition to measuring, weighing, and sexing the fish, we again took samples of pollock stomachs and otoliths. We conducted two fish hauls during my shift and we will probably do two more tonight.

Testes of a male Walleye Pollock

When we finish collecting the data we must clean the lab. The best part of this cleanup is that the dissected fish become food for the numerous Northern Fulmars trailing our ship and then the lab is simply hosed down, including the computers! We clean the lab after every fishing event because if the fish scales dry out, they become impossible to remove, much like cereal crusted in a bowl! Not to mention all the fish parts would become unbearable stinky when we have a rare, sunny, warm day!

Pollock stomach contents: Amphipods (dark) and some type of fish.

Personal Log:
When I walked outside to observe the activity on the deck (where the fishing nets are located in the back of the ship) the fog was very thick. Of course, living in Dutch Harbor, I have become accustomed to such conditions but being out on the boat gave me an entirely new feeling. The boat rocked calmly, pitching every-so-often and overall there was an eerie silence among the crashing of the waves. The fog creeped aboard the boat drifting like fingers into every space available and subtly created a chill when it brushed against your neck. I can understand why sailors are prone to superstitious beliefs.

Northern Fulmars trailing the boat on the starboard side.

Later, the weather cleared into a gorgeous blue sky and the golden sun glistened on the water. I had an exciting day as I was allowed to launch an XBT and able to advance my skills in fish dissecting as I extracted stomachs and otoliths along with my regular fish duties of sorting, sexing, and measuring.
Today was a full day of work and when I when I walked into the mess hall for supper, I could not believe my eyes. There is nothing better than having a chef aboard a ship that cares for his crew. There was turkey, ham, bread dressing, mashed potatoes, cranberry sauce, candied yams, salmon tetrazzini, brown gravy, Tom Yumm Soup, dinner rolls, and corn bread! In addition, we had the lovely view of food art as our chef Ray Capati created a swan out of an apple, bouquets of baby bok choy and celery, “water lilies” made of grapefruit or oranges and mixed with flowers, and palm trees made of carrots and green bell peppers! I feel like I’m eating in a 5-star restaurant aboard the Oscar Dyson!

Ray Capati behind another fantastic, aesthetically pleasing buffet!

Animals Spotted Today:
Today is known by the “birders” from the US Fish and Wildlife folks as the Day of the Jaeger because we were able to see all three species: Longtail, Parasitic, and Pomarine!
Northern Fulmars
Black-legged Kittiwake
Common Murre
Thickbilled Murre

Slaty-backed Gull

Least Auklet
Slaty-backed Gull (Russian seagull)
Jellyfish (Chrysaora Melanaster)
Walleye Pollock
Rock Sole
Silver Salmon (Coho)
Arrowtooth Flounder
Digested shrimps, euphausiids, amphipods, and copepods from pollock stomachs!

Something to Ponder:
Random samples are important in scientific observations because we want to obtain a general idea of what is in the ocean. Imagine if a scientist only selected the largest pollock caught in the codend. How would that skew the data samples and the information given to the public about the pollock in the ocean?

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