NOAA Teacher at Sea
Aboard NOAA Ship Oscar Dyson
July 26 – August 13, 2014
Mission: Annual Walleye Pollock Survey
Geographical Area: Bering Sea
Date: August 2, 2014
Science and Technology Log
See this guy here? He’s an Alaskan Pollock.
“Whatever,” you shrug.
“Just a fish,” you scorn.
“He’s slimy and has fish for brains,” you mock.
Well, what if I told you that guy there was worth almost one billion dollars in exports alone?
What if I told you that thousands of fishermen rely on this guy to provide for their families?
What if I told you that they were the heart of the Sub-Arctic food web, and that dozens of species would be threatened if they were to disappear?
What if I told you they were all secretly trained ninja fish? Ninja fish that carry ninja swords strapped to their dorsal fins?
Then I’d only be wrong about one thing.
Taina Honkalehto is the Chief Scientist onboard the Oscar Dyson. She has been studying Pollock for the last 22 years. I asked her what was so important about the fish.
“They’re the largest single species fishery in North America,” Taina says. That makes them top dog…err… fish… in the U.S. fishing industry.
“In the U.S. they are fish sticks and fish-wiches (like Filet-o-Fish from McDonalds). They’ve become, foodwise, what Cod used to be… inexpensive, whitefish protein,” Taina continues. They’re also the center of the sub-arctic food web. Seals, walruses, orca, sea lions, and lots of larger fish species rely on Pollock as an energy source.”
But they aren’t just important for America. Pollock plays an important role in the lives of people from all over the Pacific Rim. (Remember that the Pacific Rim is made up of all the countries that surround the Pacific Ocean… from the U.S. and Canada to Japan to Australia to Chile!)
“Pollock provide a lot of important fish products to many countries, including the U.S., Japan, China, Korea, and Russia,” Honkalehto says.
Making sure we protect Pollock is REALLY important. To know what can go wrong, we only have to look at the Atlantic Cod, the fish that Cape Cod was named after. In the last twenty years, the number of Atlantic Cod has shrunk dramatically. It’s cost a lot of fishermen their jobs and created stress in a number of families throughout New England as well as tensions between the U.S. and Canada. The U.S. and Canada share fish populations.
The primary job of the Oscar Dyson is to sample the Pollock population. Government officials use the results to tell fishermen what their quota should be. A quota is a limit on the number of fish you can catch. The way we gather that data, though, can be a little gross.
The Aleutian Wing Trawl (or AWT)
The fishermen guide the massive Aleutian Wing Trawl (or AWT) onto the deck of the ship. The AWT is a 150 meters long net (over one and a half football fields in length) that is shaped like an ice cream cone. The net gets more and more narrow until you get all the way down to the pointy tip. This is known as the “cod end,” and it’s where most of the fish end up. Here’s a diagram that XO (Executive Officer) Kris Mackie was kind enough to find for me.
The AWT is then hooked onto a crane which empties it on a giant mechanical table. The table has a hydraulic lift that lets us dump fish into the wet lab.
Kids, whenever you hear the term “wet lab,” I don’t want you to think of a water park. Wet lab is going to mean guts. Guts and fish parts.
In the wet lab, the contents of the net spills onto a conveyer belt… sort of like what you see at Shaw’s or Market Basket. First we sift through the Pollock and pull any odd things… jellyfish, skates, etc… and set them aside for measurement. Then it’s time to find out what sex the Pollock are.
Genitals on the Inside!
Pollock go through external fertilization (EF). That means that the female lays eggs, and the males come along and fertilize them with their sperm. Because of that, there’s no need for the outside part of the sex organs to look any different. In science, we often say that form follows function. In EF, there’s very little function needed other than a hole for the sperm or egg cells to leave the body.
Because of that, the only way to tell if a Pollock is male or female is to cut them open and look for ovaries and testes. This is a four step process.
Step 1: Slice open the belly of the fish.
Step 2: Push the pink, flippy floppy liver aside.
Step 3: Look for a pair of lobes (a bag like organ) that is either purple, pink, or orange-ish. These are the ovaries! If you find this, you’ve got a female.
Step 4: If you strike out on step 3, look for a thin black line that runs behind the stomach. These are the testes… As Tom Hanks and Meg Ryan might say, you’ve got male.
Then the gender and length of the fish is then recorded using CLAMS… a software program that NOAA computer scientists developed for just this purpose. With NOAA, like any good science program, it’s all about attention to detail. These folks take their data very seriously, because they know that so many people depend on them to keep the fish population safe.
On the first day aboard the Oscar Dyson, we were trained on all matters of safety. Safety on a ship is often driven by sirens sounded by the bridge. Here’s a list of calls, what they mean, and what you should do when you hear them:
|What you hear…||What it means…||What you should do…|
|Three long blasts of the alarm:||Man Over Board||Report to safety station, be counted, and report in to the bridge (unless you’re the one that saw the person go overboard… then you throw them life rings (floaties) and keep pointing at them).|
|One long blast of general alarm or ship’s whistle:||Fire or Emergency onboard||Report to safety station, be counted, and report in to the bridge. Bring Immersion Suit just in case.|
|Six or more short blasts then one long blast of the alarm:||Abandon Ship||Grab your immersion suit, head to the aft (back) deck of the ship, be counted, and prepare to board a life raft.|
The immersion suit (the thing that makes me look like lobster gumby, above) is made of thick red neoprene. It has two flashing lights also known as beacons… one of them automatically turns on when it hits water! This helps rescuers find you in case you’re lost in the dark. It also has an inflatable pillow behind your head to help keep your head above water. Mostly just wanted to wear it to Starbucks some day.
Another thing I can tell you about life aboard the Oscar Dyson is that there is plenty to eat!
kind of awesome. For one thing, there is a never ending supply of food in the galley (the ship’s cafeteria). Eva is the Chief Steward on the Oscar Dyson (though I call her the Head Chef!).
You’ll never go hungry on her ship. Dinner last night? barbeque ribs and mac and cheese. Yesterday’s lunch? Steak and chicken fajitas. And this morning? Breakfast burritos with ham and fruit. I know. You were worried that if I lost any weight at sea that I might just disappear. I can confirm for you that this is absolutely not going to happen.
Tune in next time when I take you on a tech tour of the Oscar Dyson!