walleye pollock – NOAA Teacher at Sea Blog

July 8, 2018July 11, 2018

Joan Shea-Rogers: Ready, Set, Go… Fish, July 6, 2018

NOAA Teacher at Sea

Joan Shea-Rogers

Aboard NOAA ship Oscar Dyson

July 1-22, 2018

Mission: Walleye Pollock Acoustic Trawl Survey

Geographic Area of Cruise: Eastern Bering Sea

Date: July 6, 2018

Weather Data from the Bridge

Latitude: 56º20.3730N

Longitude: 170.39 7756W

Sea Wave Height: 3-4 feet

Wind Speed: 18.87 Knots

Wind Direction: 126º true

Visibility: 2miles

Air Temperature: 8.7ºC

Barometric Pressure: 1002.0 milibars

Sky: Overcast

Science and Technology Log

Note: This Walleye Pollock Acoustic Trawl Survey is a way to estimate the amount of fish that are present in a targeted area of the Bering Sea. NOAA Scientists have been conducting these surveys since the 1970’s. It is important work necessary to manage the pollock population. (Pollock is a billion dollar food industry, thus a very important ocean resource.) These population estimates are part of the information used to determine how much fish can be caught in the Bering Sea (fishing quotas, MSY-Maximum Sustainable Yield) that still allows the population to reproduce and survive in adequate numbers.

Ready:

What does it take to prepare for an Acoustic Trawl Survey?

The fisheries scientists plan their sampling area based upon past surveys so that each part of the Bering Sea is covered over a period of time, in this case June through August;decisions must be made about who will be going on which leg of each trip. They also determine what research projects will be conducted, what specimens should be collected, and what information they need to obtain from this work. Other scientists also make requests, such as specimen collections or oceanography equipment deployments in target areas to obtain information for their own research projects. A document called Project Instructions is developed to include these cruise objectives and a list of all the supplies and equipment needed to conduct the research projects. Once the Project Instructions document is complete, it must be sent for review to NOAA administration, then to MOC-P (Marine Operations Center-Pacific)- which is a home location for NOAA to monitor its’ fleet of NOAA vessels. Now on to the NOAA Corps officers who are also preparing the ship for this cruise. In cases of requesting to sample the western Bering Sea (near, but outside of Russian waters), the State Department must approve it. Once this plan has been approved, many preparation activities begin.

SET:

A detailed spreadsheet is developed that lists all supplies needed for the fishing and research work. This includes vials for sampling, chemicals for preserving, tools needed to conduct research, and fishing gear. Some supplies are loaded on the ship when in port in Dutch Harbor or Kodiak, but other supplies are shipped in shipping containers or flatbed trailers. A large ship carries these on the ocean from Seattle to Dutch Harbor, and then tractor trailers bring the nets to the ship.

Go:

Then scientists work with the ship’s crew to make final decisions regarding haul locations. While the general area to fish is determined prior to setting sail, specific haul locations (along survey tracklines or transects) are determined as the scientists monitor the location and distribution of fish using sonar readings during sailing.

Personal Log:

I am enjoying life at sea and settling into the maritime routines that ensure the ship runs smoothly. NOAA ship Oscar Dyson is a small city with each person having very specific responsibilities for safety and operations. There are approximately 30 people on board. My work shift is from 4pm – 4 am each day. (There are no days off.) The ship has 5 labs (Wet lab, Dry lab, Acoustics Lab, Chemical Lab, Fish Lab) I spend my work shift after each haul, in the fish lab. There we identify the species that are caught, collect specimens for research and record weights and measurements of targeted species. This allows calculation of the amount of each species caught, which are used to calculate population estimates. (This is called processing the catch.) I also spend time writing blog posts, planning lessons about the work here, and interviewing staff on board to learn about their career paths. I will also use this information to teach students about the science related to this work and the career opportunities in this field. Well, a net is being pulled up now, so off to the fish lab I go.

A Sunny Day Out On the Deck — A sunny day out on the deck of NOAA ship Oscar Dyson

Joan Shea-Rogers aboard NOAA ship Oscar Dyson before sailing

Did You Know?

Sonar readings can be used to “see” what is in the water column. This is due to sound waves that bounce off what is in the water (“echoes”). Strong echoes come from pollock because sound waves bounce off the gas in their swim bladders. These echoes can be shown on a computer screen as the ship sails along, making a plot called an “echogram”.

July 13, 2015August 11, 2021

Andrea Schmuttermair, Pollock Processing Gone Wild, July 12, 2015

NOAA Teacher at Sea
Andrea Schmuttermair
Aboard NOAA Ship Oscar Dyson
July 6 – 25, 2015

Mission: Walleye Pollock Survey
Geographical area of cruise: Gulf of Alaska
Date: July 12, 2015

Weather Data from the Bridge:
Latitude: 55 25.5N
Longitude: 155 44.2W
Sea wave height: 2ft
Wind Speed: 17 knots
Wind Direction: 244 degrees
Visibility: 10nm
Air Temperature: 11.4 C
Barometric Pressure: 1002.4 mbar
Sky: Overcast

Science and Technology Log

I’m sure you’re all wondering what the day-to-day life of a scientist is on this ship. As I said before, there are several projects going on, with the focus being on assessing the walleye pollock population. In my last post I talked about the transducers we have on the ship that help us detect fish and other ocean life beneath the surface of the ocean. So what happens with all these fish we are detecting?

The echogram that shows data from the transducers.

The transducers are running constantly as the ship runs, and the information is received through the software on the computers we see in the acoustics lab. The officers running the ship, who are positioned on the bridge, also have access to this information. The scientists and officers are in constant communication, as the officers are responsible for driving the ship to specific locations along a pre-determined track. The echograms (type of graph) that are displayed on the computers show scientists where the bottom of the ocean floor is, and also show them where there are various concentrations of fish.

This is a picture of pollock entering the net taken from the CamTrawl.

When there is a significant concentration of pollock, or when the data show something unique, scientists might decide to “go fishing”. Here they collect a sample in order to see if what they are seeing on the echogram matches what comes up in the catch. Typically we use the Aleutian wing trawl (AWT) to conduct a mid-water trawl. The AWT is 140 m long and can descend anywhere from 30-1,000 meters into the ocean. A net sounder is mounted at the top of the net opening. It transmits acoustic images of fish inside and outside of the net in real time and is displayed on a bridge computer to aide the fishing operation. At the entrance to the codend (at the end of the net) a CamTrawl takes images of what is entering the net.

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Once the AWT is deployed to the pre-determined depth, the scientists carefully monitor acoustic images to catch an appropriate sample. Deploying the net is quite a process, and requires careful communication between the bridge officers and the deck crew. It takes about an hour for the net to go from its home on deck to its desired depth, and sometimes longer if it is heading into deeper waters. They aim to collect roughly 500 fish in order to take a subsample of about 300 fish. Sometimes the trawl net will be down for less than 5 minutes, and other times it will be down longer. Scientists are very meticulous about monitoring the amount of fish that goes into the net because they do not want to take a larger sample than needed. Once they have determined they have the appropriate amount, the net is hauled back onto the back deck and lowered to a table that leads into the wet lab for processing.

Here the scientists, LT Rhodes, and ENS Kaiser assess the catch.

We begin by sorting through the catch and pulling out anything that is not pollock. We don’t typically have too much variety in our catches, as pollock is the main fish that we are after. We have, however, pulled in a few squid, isopods, cod, and several jellies. All of the pollock in the catch gets weighed, and then a sub-sample of the catch is processed further. A subsample of 30 pollock is taken to measure, weigh, collect otoliths from, and occasionally we will also take ovaries from the females. There are some scientists back in the lab in Seattle that are working on special projects related to pollock, and we also help these scientists in the lab collect their data.

The rest of the sub-sample (roughly 300 pollock) is sexed and divided into a male (blokes) and female (sheilas) section of the table. From there, the males and females are measured for their length. The icthystick, the tool we use to measure the length of each fish, is pretty neat because it uses a magnet to send the length of the fish directly to the computer system we use to collect the data, CLAMS. CLAMS stands for Catch Logger for Acoustic Midwater Survey. In the CLAMS system, a histogram is made, and we post the graphs in the acoustics lab for review. The majority of our pollock so far have been year 3. Scientists know this based on the length of pollock in our catch. Once all of the fish have been processed, we have to make sure to clean up the lab too. This is a time I am definitely thankful we have foul weather gear, which consists of rubber boots, pants, jackets and gloves. Fish scales and guts can get everywhere!

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Personal Log

Here is one of many jellies that we caught. .

I am finally adjusting to my nighttime shift schedule, which took a few days to get used to. Luckily, we do have a few hours of darkness (from about midnight until 6am), which makes it easier to fall asleep. My shift runs from 4pm-4am, and I usually head to bed not long after my shift is over, and get up around noontime to begin my day. It’s a little strange to be waking up so late in the day, and while it is clearly afternoon time when I emerge from my room, I still greet everyone with a good morning. The eating schedule has taken some getting used to- I find that I still want to have breakfast when I get up. Dinner is served at 5pm, but since I eat breakfast around 1 or 2pm, I typically make myself a plate and set it aside for later in the evening when I’m hungry again. I’ll admit it’s a little strange to be eating dinner at midnight. There is no shortage of food on board, and our stewards make sure there are plenty of snacks available around the clock. Salad and fruit are always options, as well as some less healthy but equally tasty snacks. It’s hard to resist some of the goodies we have!

Luckily, we are equipped with some exercise equipment on board to battle those snacks, which is helpful as you can only walk so far around the ship. I’m a fan of the rowing machine, and you feel like you’re on the water when the boat is rocking heavily. We have some free weights, an exercise bike and even a punching bag. I typically work out during some of my free time, which keeps me from going too crazy when we’re sitting for long periods of time in the lab.

Up on the bridge making the turn for our next transect.

During the rest of my free time, you might find me hanging out in the lounge watching a movie (occasionally), but most of the time you’ll find me up on the bridge watching for whales or other sea life. The bridge is probably one of my favorite places on the ship, as it is equipped with windows all around, and binoculars for checking out the wildlife. When the weather is nice, it is a great place to sit outside and soak in a little vitamin D. I love the fact that even the crew members that have been on this ship for several years love seeing the wildlife, and never tire of looking out for whales. So far, we’ve seen orcas, humpbacks, fin whales, and Dall’s porpoises.

Did you know? Otoliths, which are made of calcium carbonate, are unique to each species of fish.

Where on the ship is Wilson?

Wilson the ring tail camo shark is at it again! He has been exploring the ship even more and made his way here. Can you guess where he is now?

August 14, 2014August 21, 2021

Kacey Shaffer: All Good Things… August 13, 2014

NOAA Teacher at Sea

Kacey Shaffer

Aboard NOAA Ship Oscar Dyson

July 26 – August 13, 2014

Mission: Walleye Pollock Survey

Geographical Location: Bering Sea

Date: August 13, 2014

Weather information from the Bridge:

Air Temperature: 12º C

Wind Speed: 10 knots

Wind Direction: 306.62 º

Weather Conditions: Clear

Latitude: 53º 51.38 N

Longitude: 166º 34.85 W

Science and Technology Log:

Before we get into detail about data and where all of it ends up, let’s talk acronyms. This trip has been a lot like working in the Special Education world with what we like to call “Alphabet Soup.” We use acronyms a lot and so does the NOAA Science world. Here are a few important acronyms…

AFSC – Alaska Fisheries Science Center (located in Seattle, WA)

MACE – Midwater Assessment and Conservation Engineering Program (also in Seattle)

CLAMS – Catch Logger for Acoustic Midwater Surveys

Drop TS – Dropped Target Strength System

CTD – Conductivity, Temperature and Depth System

SBE – Sea-bird Electronics Temperature-Depth Recorder

We recorded data in a program called CLAMS as we processed each haul. The CLAMS (see above: Catch Logger for Acoustic Midwater Surveys) software was written by two NOAA Scientists. Data can be entered for length, weight, sex and development stage. It also assigns a specimen number to each otolith vial so the otoliths can be traced back to a specific fish. This is the CLAMS screen from my very first haul on the Oscar Dyson.

Kacey's first haul on the Oscar Dyson. — Kacey’s first haul on the Oscar Dyson.

From the Species List in the top left corner you can see I was measuring the length of Walleye Pollock- Adult. In that particular haul we also had Age 2 Pollock, a Chum Salmon and Chrysaora melanaster (a jellyfish or two). There is the graph in the lower left corner that plots the sizes in a bar graph and the summary tells me how many fish I measured – 462! When we finish in the Wet Lab we all exit out of CLAMS and Robert, a zooplankton ecologist working on our cruise, ducks into the Chem Lab to export our data. There were a total of 142 hauls processed during the 2014 Summer Walleye Pollock Survey (June 12 – August 13) so this process has happened 142 times in the last two months!

Next, it is time to export the data we collected onto a server known as MACEBASE. MACEBASE is the server that stores all the data collected on a Pollock survey. Not only will the data I helped collect live in infamy on MACEBASE, all the data collected over the last several years lives there, too. CLAMS data isn’t the only piece of data stored on MACEBASE. Information from the echosounding system, and SBE (Sea-bird Electronics temperature depth recorder) are uploaded as well.

We’ve reached the end of the summer survey. Now what? 142 hauls, two months of echosounder recordings, four Drop TS deployments and 57 CTD’s. There have also been 2660 sets of otoliths collected. Scientists who work for the MACE program will analyze all of this information and a biomass will be determined. What is a biomass? Some may think of it as biological material derived from living or recently living organisms. In this case, biomass refers to the total population of Walleye Pollock in the Bering Sea. In a few weeks our Chief Scientist Taina Honkalehto will present the findings of the survey to the Bering Sea Plan Team.

That team reviews the 2014 NOAA Fisheries survey results and Pollock fishing industry information and makes science-based recommendations to the North Pacific Fishery Management Council, who ultimately decide on Walleye Pollock quotas for 2015. Think about Ohio’s deer hunting season for a minute. Each hunter is given a limit on how many deer they can tag each year. In Pickaway & Ross counties we are limited to three deer – two either sex permits and one antlerless permit. If every deer hunter in Ohio was allowed to kill as many deer as they pleased the deer population could be depleted beyond recovery. The same goes for Pollock in the Bering Sea. Commercial fisheries are given quotas and that is the maximum amount of Pollock they are allowed to catch during a given year. The scientific research we are conducting helps ensure the Pollock population remains strong and healthy for years to come.

Personal Log:

Earlier today I took a trip down to the Engine Room. I can’t believe I waited until we were almost back to Dutch Harbor to check out this part of the ship. The Oscar Dyson is pretty much a floating city! Put on some ear protection…it’s about to get loud!

Kacey stands by one of four diesel engines on the Oscar Dyson. (Photo credit: Sweet William)

Why must we wear ear protection? That large machine behind me! It is a 3512 Caterpillar diesel engine. The diesel engine powers an electric generator. The electric generator gives power to an electric motor which turns the shaft. There are four engine/generator set ups and one shaft on the Dyson. The shaft turns resulting in the propeller turning, thus making us move! When we are cruising along slowly we can get by with using one engine/generator to turn the shaft. Most of the time we are speeding along at 12 knots, which requires us to use multiple engines/generators to get the shaft going. Here is a shot of the shaft.

The EOS, or Engineering Operation Station, is the fifth location where the ship can be controlled. The other four locations are on the Bridge.

Engine Data Screen provides information about the engines, generators and shaft.

This screen provides Engineers with important info about the generators (four on board) and how hard they’re working. At the time of my tour the ship was running on two generators (#1 and #2) as shown on the right side of the screen. #3 and #4 were secured, or taking a break. The Officer of the Deck, who is on the Bridge, can also see this screen. You can see an Ordered Shaft RPM (revolutions per minute) and an Actual Shaft RPM boxes. The Ordered Shaft RPM is changed by the Officer on Deck depending on the situation. During normal underway conditions the shaft is running at 100-110 RPMs. During fishing operations the shaft is between 30 and 65 RPMs.

When I talked about the trawling process I mentioned that the Chief Boatswain is able to extend the opening of the net really far behind the stern (back) of the ship. This is the port side winch that is reeled out during trawling operations. There are around 4300 meters of cable on that reel! How many feet is that?

The rudder of the Oscar Dyson is right below this part of the hydraulic system.

Part of the hydraulic system on the Oscar Dyson.

When Lt. Ostapenko and ENS Gilman were teaching me how to steer this ship they emphasized how sensitive the steering wheel is. Only a little fingertip push to the left can really make a huge difference in the ship’s course. This is the hydraulic system that controls the rudder, which steers the ship left or right. The actual rudder is hidden down below, under water. I’m told it is a large metal plate that stands twice as tall as me. This tour really opened my eyes to a whole city that operates below the deck I’ve been working on for the last 18 days. Without all of these pieces of equipment long missions would not be possible. Because the Oscar Dyson is well-equipped it is able to sail up to forty days at a time. What keeps it from sailing longer voyages? Food supply!

And just like that I remembered all good things must come to an end. This is the end of the road for the Summer Walleye Pollock Survey and my time with the Oscar Dyson. We have cleaned and packed the science areas of the ship. Next we’ll be packing our bags and cleaning our staterooms. In a matter of hours we’ll be docking and saying our goodbyes. There have been many times over the last 19 days where I’ve stood, staring out the windows of the Bridge and thinking about how lucky I am. I will never be able to express how thankful I am for this opportunity and how it will impact my life for many, many years. A huge THANK YOU goes to the staff of NOAA Teacher at Sea. My fellow shipmates have been beyond welcoming and patient with me. Thank you, thank you, THANK YOU to everyone on board the Dyson!! I wish you safe travels and happy fishing!

To Team Bluefin Tuna (night shift Science Crew), thank you for your guidance, ice cream eating habits, card game instruction, movie watching enthusiasm, many laughs and the phrase “It is time.” Thanks for the memories! I owe y’all big time!

Did you know? The ship also has a sewage treatment facility and water evaporation system onboard. The MSD is a septic tank/water treatment machine and the water evaporation system distills seawater into fresh potable (drinking and cooking) water.

A shot of Captain’s Bay from the Flying Bridge of the Oscar Dyson. (Photo credit: Robert)

Kacey on the Flying Bridge of the Oscar Dyson. (Photo credit: Emily)

Kacey on the NOAA Ship Oscar Dyson R-224. (Photo Credit: Emily)

Thanks for the memories! (Photo credit: Emily)

August 2, 2014August 21, 2021

Gregory Cook, Super Fish, August 2, 2014

NOAA Teacher at Sea

Gregory Cook

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.

If fish thought sunglasses were cool, this fish would wear sunglasses. — Alaskan Pollock, aka Walleye Pollock.
Credit: http://www.noaanews.noaa.gov

“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.

Chief Scientist Taina Honkalehto decides where to fish based on data.

“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 Aleutian Wing Trawl (or AWT). over one and a half football fields worth of Pollock-Snatching Power.

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.

Survey Technician Allen pulls a cod from the Table

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.

Survey Technician Alyssa and Oceanographer Nate pull a giant jellyfish out of a pile of pollock!

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.

Ladies before Gentlemen: The female Pollock (in the front) has ovaries that look like two orange lobes. The Male (in the back) has structures that make him look like he ate Ramen noodles for dinner. — Ladies before Gentlemen:
The female Pollock (bottom) has ovaries that look like two orange lobes. The Male (itop) has testes that make him look like he ate Ramen noodles for dinner.

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.

Personal Blog

Safety!

Lobster Gumby — Your teacher in an Immersion Suit. Sailors can survive for long periods of time in harsh environments in these outfits.

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.

Food!

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!).

Chief Steward Eva gets dinner done right!

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!

August 12, 2013March 12, 2021

Julia Harvey: We Came, We Fished, Now What? August 8, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 8/8/13

Weather Data from the Bridge (as of 17:00 Alaska Time):
Wind Speed: 15.72 knots
Temperature: 13.4 C
Humidity: 73%
Barometric Pressure: 1012.1 mb

I just read this heads up about the weather tonight.

Science and Technology Log:

We came. We fished. We measured, counted and weighed. Now What? We completed one last trawl on Tuesday night (August 6^th). When we finished we had caught over 65,000 walleye pollock and a whole lot of POP (Pacific ocean perch) on this leg of the survey.

The scientists now process and analyze the data.

Darin Jones and Chief Scientist Patrick Ressler going over data collected.

Darin and Patrick will present at a public meeting when we are back in Kodiak on Friday. They will discuss what was seen and preliminary findings of the walleye pollock survey. Back in Seattle the MACE team will further evaluate the data along with data from the bottom trawl survey and determine the walleye pollock biomass for the Gulf of Alaska. This will then be taken under advisement by the North Pacific Fishery Management Council.

There is also the lab to clean. Even though we cleaned the lab after each trawl, it needed a good scrub down. There were scales and slime hidden everywhere. Just when you thought you were done, more scales were discovered.

Kirsten, Abigale and Darin cleaning the fish lab.

Did You Know?

The note on the white board stated that there will be beam seas tonight. What does that really mean? It means the waves are moving in a direction roughly 90° from our heading. So the water will be hitting us at a right angle to our keel. It will be a rocking boat tonight.

Darin took a sample of the salmon shark’s fin when we caught it. It will be sent to a scientist in Juneau who works at Auke Bay Laboratories (where Jodi works). The sample will be used to examine the population genetics of the salmon shark and other species such as the Pacific sleeper shark.

Personal Log:

In my first blog, I wrote about a childhood dream of becoming an oceanographer. After my third year of teaching in the Peace Corps, I decided education was my new direction. I was excited to taste that bygone dream aboard the Oscar Dyson. How do I feel now? I jokingly sent an email to my assistant principal telling her to look for a new science teacher because I love life at sea. I love collecting data in the field. Although I was not responsible for analyzing the data and I do miss my boys, I had an awesome cruise. So where does that leave me?

Heading to Kodiak across the Gulf of Alaska

It leaves me back in the classroom with an amazing sea voyage experience to share with my students. I will always long for that oceanographic career that could have been. But perhaps after my experience, I will inspire future oceanographers and fisheries scientists. And I would do Teacher at Sea again in a heartbeat. I will follow up with the outcomes and biomass estimates from MACE (Mid-Water Assessment & Conservation Engineering) and I will most definitely follow Jodi’s research on the use of multibeam sonar for seafloor mapping.

I want to say thank you to everyone who made my experience one of the best of my life and definitely the best professional development of my career. Thank you to Jennifer Hammond, Elizabeth McMahon, Jennifer Annetta, Emily Susko and Robert Ostheimer for the opportunity to participate in the NOAA Teacher at Sea Program. Thank you to NOAA for developing a practical and realistic opportunity to connect my students to ocean science. Thank you to the science team (Chief Scientist Patrick Ressler, Darin Jones, Paul Walline, Jodi Pirtle, Kirsten Simonsen, and Abigale McCarthy) aboard the Oscar Dyson for their willingness to train me, answer all of my questions, preview my blogs, and to allow me have a glimpse of their lives as scientists. Thank you to Patrick Ressler and XO Chris Skapin for promptly providing feedback on my blogs. And a special thanks to the night shift crew (Jodi, Paul and Darin). I was very nervous about adjusting to my work hours (4 pm to 4 am) especially after falling asleep that first night, but I am very grateful for colleagues who were fascinating and night-time enjoyable. Chats with everyone aboard the Oscar Dyson from fishermen to NOAA Corps to engineers to stewards to scientists were educational and pleasant. I met lots of people from all over the U.S. and some just from Newport (2 hours from Eugene).

WOW. How fortunate was I to be chosen? I am nearly speechless about what I saw and what I did. What a mind blowing three weeks. Thank You! Thank You! Thank You!

Now I begin the transition of living during daylight hours.

I hope everyone was able to sample a little of my adventure. I appreciate everyone who followed my blog especially Camas Country Mill folks.

August 9, 2013March 12, 2021

Julia Harvey: Calibration in Sea-Otterless Sea Otter Bay, August 7, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 8/7/13

Weather Data from the Bridge (as of 21:00 Alaska Time):
Wind Speed: 10.42 knots
Temperature: 13.6 C
Humidity: 83%
Barometric Pressure: 1012.4 mb

Current Weather: A high pressure system is building in the east and the swells will increase to 8 ft tonight.

Science and Technology Log:

Before I begin, I must thank Paul for educating me on the calibration process. Because calibration occurred during the day shift, I was not awake for some of it.

The EK60 is a critical instrument for the pollock survey. The calculations from the acoustic backscatter are what determines when and where the scientists will fish. Also these measurements of backscatter are what are used, along with the estimates of size and species composition from the trawling, to estimate fish biomass in this survey. If the instruments are not calibrated then the data collected would possibly be unreliable.

Calibration of the transducers is done twice during the summer survey. It was done before leg one in June, which began out of Dutch Harbor, and again now near Yakutat as we end leg three and wrap up the 2013 survey.

As we entered Monti Bay last night, Paul observed lots of fish in the echosounder. This could pose a problem during calibrations. The backscatter from the fish would interfere with the returns from the spheres. Fortunately fish tend to migrate lower in the water column during the day when calibrations were scheduled.

This morning the Oscar Dyson moved from Monti Bay, where we stopped last night, into Sea Otter Bay and anchored up. The boat needs to be as still as possible for the calibrations to be successful.

Monti and Sea Otter Bays Map by GoogleEarth — Monti and Sea Otter Bays
Map by GoogleEarth

Calibration involves using small metal spheres made either of copper or tungsten carbide.

Chief Scientist Patrick Ressler with a tungsten carbide sphere

Copper sphere photo courtesy Richard Chewning (TAS) — Copper sphere
photo courtesy Richard Chewning (TAS)

The spheres are placed in the water under transducers. The sphere is attached to the boat in three places so that the sphere can be adjusted for depth and location. The sphere is moved throughout the beam area and pings are reflected. This backscatter (return) is recorded. The scientists know what the strength of the echo should be for this known metal. If there is a significant difference, then data will need to be processed for this difference.

The 38 khz transducer is the important one for identifying pollock. A tungsten carbide sphere was used for its calibration. Below shows the backscatter during calibration, an excellent backscatter plot.

The return for this sphere was expected to be -42.2 decibels at the temperature, salinity and depth of the calibration The actual return was -42.6 decibels. This was good news for the scientists. This difference was deemed to be insignificant.

Personal Log:

Calibration took all of the day and we finally departed at 4:30 pm. The views were breathtaking. My camera doesn’t do it justice. Paul and Darin got some truly magnificent shots.

As we left Yakutat Bay, I finally saw a handful of sea otters. They were never close enough for a good shot. They would also dive when we would get close. As we were leaving, we were able to approach Hubbard Glacier, another breathtaking sight. Despite the chill in the air, we stayed on top getting picture after picture. I think hundreds of photos were snapped this evening.

Location of Hubbard Glacier. Map from brentonwhite.com

Many came out in the cool air to check out Hubbard Glacier

Lots of ice from the glacier as we neared

Nearby Hubbard Glacier with no snow or ice — Near Hubbard Glacier

Did You Know?

According to the National Park Service, Hubbard Glacier is the largest tidewater glacier in North America. At the terminal face it is 600 feet tall. This terminal face that we saw was about 450 years old. Amazing!

Julia Harvey: Here Fishy Fishy/Prince William Sound, August 1, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 8/1/13

Weather Data from the Bridge (as of 00:00 Alaska Time):
Wind Speed: 12 knots
Temperature: 13 C
Humidity: 97 %
Barometric Pressure: 1021 mb

Science and Technology Log:

The main goal of Leg 3 of this mission is to use acoustics and trawling to survey the mid-water portion of the pollock population along the Gulf of Alaska starting near Kodiak to Yakutat Bay.

Pollock live in the an area between the middle of the water column and the seafloor. Sometimes we sample the mid-water and sometimes we will sample the bottom.

bump-food-web_600 — Location of Fish in Water Column

The Oscar Dyson carries three different types of trawling nets for capturing fish as part of the mid-water survey: the Aleutian Wing Trawl (AWT), a mid-water trawl net, the Poly Nor’Eastern (PNE), for bottom trawls and the Methot, which is for gathering samples of very small ocean creatures such as krill. I will focus on the AWT, although some of the video footage is from a bottom trawl.

Scale model of the Aleutian Wing Trawl (AWT) net courtesy of NOAA Scientist Kresimir Williams

When the net is deployed from the ship, the first part of the net to hit the water is called the codend. This is where most of the fish end up after the trawl. The mesh size of the net is smallest at the codend (about 1 cm) and gets larger as it approaches the doors (about 1 m).

A Cam Trawl goes in the water next. This is a pair of cameras that help scientists identify and measure the fish that are caught in the net. This technology can also be used to help scientists validate their biomass estimate from trawling sampling counts. This piece of equipment has to be clipped into loops on the trawl each time.

The trawl camera is attached to the net to monitor the fish entering the net.

The next piece of the net to hit the water is the “kite” which is secured to the head rope. Here, a series of sensors is attached to help the scientists gather data about the condition of the net including depth, size, and shape underwater. The major acoustic sensor, called the “turtle,” can tell if the fish are actually going into the net.

AWT Net — Close-up view of the AWT scale model to highlight the kite and the turtle that ride at the top of the net. The third wire holds the electrical wires that send data from the turtle to the bridge (courtesy of Teacher at Sea).

Once the kite is deployed, a pair of tom weights (each weighing 250 lbs), are attached to the bridal cables to help separate the head rope from the foot rope and ensure the mouth of the net will open. Then, after a good length of cable is let out, the crew transfers the net from the net reel to the two tuna towers and attach the doors. The doors create drag to ensure the net mouth opens wide.

The scientists use acoustic data to determine at what depth they should fish, then the OOD (Officer on Deck) uses a scope table to determine how much cable to let out in order to reach our target depth. Adjustments to the depth of the head rope can be made by adjusting speed and/or adjusting the length of cable released.

The scientists use the acoustic data sent from the “turtle” to determine when enough fish are caught to have a scientifically viable sample size, then the entire net is hauled in.

Once on board, the crew uses a crane to lift the cod end over to the lift-table. The lift-table then dumps the catch into the fish lab where the fish get sorted on a conveyor belt.

Personal Log:

The Oscar Dyson needed to pick up materials for a net repair so we headed into Prince William Sound towards Valdez. The area was spectacular.

Julia Harvey — Here I am in Prince William Sound

The sun was out and the skies were blue for most of the day. Although we have had very calm seas, we have been under clouds for most of the last few days.

Enjoying the Sun — A handful of people gathered at the bow of the ship to enjoy the sun and the sights.

The absolute highlight of the day was spotting Dall porpoises and filming them bow surfing.

Here are snapshots of the day. The area was so impressive that I have several hundred pictures. Here are just a few:

Click here to learn more about the Columbia glacier and to watch the changes to the glacier over time.

I am reminded of the Exxon Valdez oil spill devastation.

Did You Know?

The Exxon Valdez (oil tanker) ran aground on Bligh Reef in Prince William Sound, Alaska on March 24, 1989.

The amount of oil spilled into this pristine environment exceeded 11 million gallons of crude oil and affected over 1300 miles of shoreline. According to OCEANA, as many as 2,800 sea otters, 300 harbor seals, 900 bald eagles and 250,000 seabirds died in the days following the disaster.

Jodi, who works the night shift with me, grew up in Cordova, Alaska and as a child remembers the smell of the disaster and the fears in her town (many were fishermen).

Has the area recovered? Part of the settlement with Exxon established a fund to support research. Read more.

July 31, 2013March 12, 2021

Julia Harvey: Listening to Fish/How I Spent My Shift, July 28, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 7/28/13

Weather Data from the Bridge (as of 18:00 Alaska Time):
Wind Speed: 15.61 knots
Temperature: 13.71 C
Humidity: 91%
Barometric Pressure: 1023 mb

Science and Technology Log:

How do scientists use acoustics to locate pollock and other organisms?

Scientists aboard the NOAA Research Vessel Oscar Dyson use acoustics, to locate schools of fish before trawling. The Oscar Dyson has powerful, extremely sensitive, carefully calibrated, scientific acoustic instruments or “fish finders” including the five SIMRAD EK60 transducers located on the bottom of the centerboard.

Trnasducer — Scientists are using the EK60 to listen to the fish.

This “fish-finder” technology works when transducers emit a sound wave at a particular frequency and detect the sound wave bouncing back (the echo) at the same frequency. When the sound waves return from a school of fish, the strength of the returning echo helps determine how many fish are at that particular site.

The transducer sends out a signal and waits for the return echo... — The transducer sends out a signal and waits for the return echo…

Sound waves bounce or reflect off of fish and other creatures in the sea differently. Most fish reflect sound energy sent from the transducers because of their swim bladder<s, organs that fish use to stay buoyant in the water column.

The above picture shows the location of the swim bladder. (Photo courtesy of greatneck.k12.ny.us)

Click on this picture to see how sound travels from various ocean creatures through water. (Photo from sciencelearn.org)

These reflections of sound (echoes) are sent to computers which display the information in echograms. The reflections showing up on the computer screen are called backscatter. The backscatter is how we determine how dense the fish are in a particular school. Scientists take the backscatter that we measure from the transducers and divide that by the target strength for an individual and that gives the number of individuals that must be there to produce that amount of backscatter. For example, a hundred fish produce 100x more echo than a single fish. This information can be used to estimate the pollock population in the Gulf of Alaska.

The trawl data provide a sample from each school and allow the NOAA scientists to take a closer look by age, gender and species distribution. Basically, the trawl data verifies and validates the acoustics data. The acoustics data, combined with the validating biological data from the numerous individual trawls give scientists a very good estimate for the entire walleye pollock population in this location.

echogram for krill — These echograms are similar to the ones produced when we trawled for krill. Krill have a significant backscatter with the higher frequencies (bottom right screens)

Personal Log:

How I spent my shift on Saturday, July 27^th?

When I arrived at work at 4 pm, a decision was made to trawl for krill. A methot trawl is used to collect krill.

Then we set to work processing the catch. First we have to suit up in slime gear because the lab will get messy. My previous blog mentioned not wanting to count all of the krill in the Gulf of Alaska. But in this case we needed to count the krill and other species that were collected by the methot trawl.

Counting krill — I needed my reading glasses to count these small krill.

How many krill do you think we collected?

Krill Sample — This is the total krill from the first methot trawl of the night.
How many are here?

Patrick, the lead scientist, put a few specimens under the microscope so we could see the different types of krill.

The collection of krill was preserved in formaldehyde and sea water. It will be sent to Poland for further species diagnosis.

preserving krill — Scientist Darin Jones preserves the krill for shipment to Poland.

As the ship continued back on transect, I wandered in to see what Jodi and Darin were doing with the data collected last night. Jodi was processing data from the multibeam sonar and Darin was surveying the images from the drop camera. Jodi was very patient explaining what the data means. I will write more about that later. But I did feel quite accomplished as I realized my understanding was increasing.

multibeam data — These images are what Jodi was processing.

A decision was made to do another methot trawl. This time we had a huge sample.

In an approximately 50 gram sample we counted 602 individual krill. Compare this to the 1728 individuals in a 50 gram sample from the first trawl. They were much bigger this time. The total weight of the entire sample of krill was 3.584 kilograms.

How many individuals were collected in the second trawl? (Check your answer at the end of the blog)

Around midnight, Paul decided to verify an echogram by trawling.

trawl net haul — Emptying out the trawl net right next to the fish lab.

We collected data from the trawl net and the pocket net.

This trawl had a variety of specimen including Pacific Ocean perch, salmon, squid, eulachon, shrimp and pollock.

The pocket net catches the smaller organisms that escape through the trawl net.

pocket trawl — These were caught in the pocket net.

It was after 2 am by the time we had processed catch and washed down the lab. The internet was not available for the rest of my shift due to the ship’s position so I organized my growing collection of videos and pictures.

I wasn’t sure how I would handle my night shift (4 pm to 4 am) after I dozed off during the first night. Now that I have adjusted, I really enjoy the night shift. The night science team of Paul, Darin and Jodi are awesome.

Did You Know?

People who are on the Oscar Dyson live throughout the United States. They fly to meet the boat when they are assigned a cruise. Jodi is from Juneau, Alaska. Paul is from Seattle, Washington. And Darin is from Seattle/North Carolina. There are a number who are based out of Newport, Oregon.

Something to Think About:

When we are fishing, a number of birds gather behind the boat. What different sea birds are observable this time of the year in our survey area?

July 31, 2013March 12, 2021

Julia Harvey: Determining Population Size/A Day in My Life Cruising, July 27, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 7/27/13

Weather Data from the Bridge (at 1:00 am Alaskan time):

Wind Speed = 3.52 knots
Air Temperature = 13.6 C
Humidity = 94%
Barometric Pressure = 1025.5 mb

Science and Technology Log:

How can you determine the population size of species?

You could count every member of the population. This would be the most accurate but what if the population moves around a lot? What if the population is enormous and requires too much time to count each and every one? Would you want to count all of the krill in the Gulf of Alaska?

You could mark and recapture. In this method you catch individuals from the population and tag them. Data are compiled from the recaptures and the population is mathematically calculated. Halibut and many other populations are monitored this way and require fishermen to report any recaptures.

Tagged Halibut
photo courtesy of Greenland Institute of Natural Resources

Another method is sampling. The organisms in a small area are counted and then the overall population in the entire area is calculated.

line_transect — Using a transect to sample a population.
Photo courtesy of http://www.kscience.co.uk/as/module5/succession/fieldwork.htm

This picture above illustrates the use of a transect line. On various increments along the transect line, samples of populations are taken. Imagine the Oscar Dyson’s path as the measuring tape and the trawl net as the sampling square.

The overall survey area of the pollock study this summer is the northern Gulf of Alaska between the shore and the continental break. Within this area transect lines were established. These are pathways that the Oscar Dyson will travel along and periodically take samples of the fish.

Transect Plan — The pollock summer survey is broken into three legs. I am part of leg 3.
Photo courtesy of NOAA

The current set of transects are 25 nautical miles (1 nautical mile is equal to 1 minute of latitude) apart and are parallel but transects in other areas may be 2 or 5 miles apart. Transects that we are following now are located on the shelf and are perpendicular to the coastline. Transects in inlets and bays may run differently and may even zigzag.

OD Current Cruise — Leg 3 left from Kodiak and is moving eastward for the survey.
Photo courtesy of NOAA

If fish are located through acoustics, the ship will break transect (a mark is made on the map) and the ship will circle around and a sample of the population is taken by trawling. The population of pollock can then be mathematical calculated. After trawling, the ship will return to the break and continue along the transect line.

This afternoon, we were working smaller transect lines near Amatuli Trench that were 6 miles apart. It is an area that has had good pollock catches. Just when we were going to fish, a pod of fin whales was spotted in the area. So we moved to another area and hauled in quite the catch of Pacific Ocean perch.

POP Haul — After fish are caught they are processed in the fish lab. Here we are processing the Pacific Ocean perch.

It is hopeful that the Oscar Dyson will finish a transect line by nightfall and then the ship can be at the next transect by sunrise. This maximizes the time looking for fish and trawling.

Personal Log:

I am settling into life on the Oscar Dyson and have established a routine that will support my night shift (4 pm to 4 am). So how do I spend 24 hours on the ship?

I wake up around 11:45 in the morning to be able to eat lunch that is served only between 11:00 and 12:00. Because of the shift schedules, some people are bound to miss one or more of the meals. I miss breakfast because I am sleeping. We are able to request a plate of food be saved for later.

Between the end of lunch and the start of my shift, there are several things that I can do. The weather has been very nice and so I often go on deck to soak up the sun and whale watch.

Whale watching — Can you spot the fin whales?

I may need to do laundry as my clothes start to smell fishy.

Laundry Room — We are lucky to have a laundry room on board. It meant I did not have to bring many clothes.

I will also workout in one of the two gyms. The gym at the back of the boat can’t be used when trawling because of the high noise level. There is a rower, two exercise bikes, two treadmills, a cross trainer, mats and weights. I got lucky and someone installed a makeshift pull up bar.

Front exercise room — This is the exercise room towards the bow of the ship.

Back Exercise Room — This is the exercise room toward the stern of the ship.

There is also a lounge where I can read or watch DVDs. Some of the movies are still in theaters.

An hour before my shift starts, I read and take a short nap. Then, I grab a cup of coffee at 4 pm as my shift starts. I listen as the day shift fills in the evening shift about the happenings of the last 12 hours.

During my shift, there are several things that I may do. If we have fished, there will be pollock and other organisms to process.

Processing pollock — Here Jodi, Kirsten and I are processing the pollock by determining their sex. Then, they will be measuresd weighed and their otoliths removed.

After processing, we need to clean up the fish lab which involves spraying down everything include ourselves with water to remove scales and slime.

I also keep an eye on the acoustic monitors, to see what I can recognize. Paul and Darin are always willing to answer my questions (even the ones I already asked).

Acoustics Screens — The four screens of acoustic data. From these screens, Paul will determine whether to fish.

I may look at trawl camera footage or observe camera drops. Drop Camera

I also have time to work on my blog.

Work Space — I have set myself up an area in the “Cave” to write my blog.

Dinner is served at 5 pm but the mess is always open and is filled with snacks such as sandwich fixings, ice cream, yoghurt, a salad bar and pop tarts.

Whenever I get hungry at night, I just head for the mess. It is a time that I am able to chat with the crew and NOAA Corps as they come in for snacks too.

At 4 am, I make it a point to head directly to my stateroom and go to sleep. The room has a window but I can close the curtains on the portlight (window) and around my bed.

There are no weekends out here. Everyone works 7 days a week for the duration of the cruise.

Did You Know?

Usually fin whales show only their back as they surface for air. Check out my video clip and see if you can spot the whale. It wasn’t too close.

July 24, 2013March 12, 2021

Julia Harvey: Yakutat or Bust, July 23, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: July 22, 2013

Weather Data from the Bridge: (7/23/13 at 11 pm)
Wind Speed = 13 knots
Air Temperature = 12.7 C
Humidity = 93%
Barometric Pressure = 1017 mb

Science and Technology Log:

There is a great deal of hope to complete the survey, which is supposed to end near Yakutat in the southeast of Alaska. It began near the islands of Four Mountains during leg 1. We are on leg 3, the final leg this summer. Leg 3 began in Kodiak. Three Legs of the Survey

Gulf of Alaska Map — Kodiak Island is the green marker and Yakutat Bay is the red.

The purpose of this cruise is to survey the walleye pollock (Theragra chalcogramma) in the Gulf of Alaska. Pollock is a significant fishery in the United States as well as the world. Pollock is processed into fish sticks, fish patties and imitation crab. Last year, about 3 million tons of pollock were caught in North Pacific. The scientists on board will collect data to determine the pollock biomass and age structure. These data are used with results from other independent surveys to establish the total allowable pollock catch.

According to the Alaska Fisheries Science Center, pollock can grow to about 3 ½ feet and weigh about 13 lbs. More typically the pollock are approximately 50 cm (20 in) and weigh .75 kg (1.7 lbs). They live in the water column and feed on krill, zooplankton and other crustaceans. As they age they will eat juvenile pollock and other small fishes such as capelin, eulachon and herring as well. Sexual maturity is reached around age 4. Spawning and fertilization occurs in the water column in early spring. The eggs stay in the water column and once hatched are part of the zooplankton until they are free swimming.

The general process used to catch the pollock involves multiple parts. I will break down those steps in a series of blogs. But basically, acoustics are used to locate fish in the water column. Once the scientists have located the fish along the transect (transects are the paths that the ship will travel on so the scientists can collect data), the Oscar Dyson sets out a trawl equipped with a camera. The trawl is brought in and data from the catch is documented. And then the ship continues on.

Trawling is usually completed only during daylight hours. Fortunately the sun does not set here in Alaska right now until after 10 pm. When it is dark, work aboard the Oscar Dyson continues. Jodi is documenting the sea floor with a drop camera. She is looking at life that is there as well as potential threats to the trawl nets for the bottom trawl surveys.

Questions:

How do scientists use acoustics to locate pollock?
How are the transects locations determined?
How are pollock and the rest of the catch processed?
What information is retrieved from the trawl camera?
What is a bottom trawl and how is it different from a mid-water trawl?

Personal Log:

We left Kodiak at 1 pm on July 22 heading southwest.

We had 8 hours of travel time before we would reach our first transect. But before we got too far away from Kodiak, we needed to practice the three drills for the safety of everyone. The fire drill and man overboard drill required me to report to the conference room and meet up with the rest of the science team. Patrick, the lead scientist, then reported that we were all accounted for. The crew had more complex tasks of deploying a small boat and retrieving “the man overboard”.

The other drill was the abandon ship drill. We are assigned to a lifeboat and I reported to my muster on the portside of the trawl deck with my survival suit, long sleeve shirt, hat and life preserver. We will have drills weekly at anytime.

For the last two days I have been becoming oriented to the ship and to my responsibilities to the science team. Jodi, a post doctorate from Juneau gave us a tour of the boat on the first day we arrived in Kodiak. I then practiced finding all of the key parts of the ship I will need to access. I now am confident that I can find my stateroom, the mess, laundry room, both exercise spaces, acoustics lab, and fish lab. For other sites, I wander around for a while until I locate it.

A Door — Many doors on the the Oscar Dyson are water tight. They must be latched after passing through them.

My first shift began at 4 pm on Monday. There are two shifts for scientists. Some work 4 am to 4 pm and the others work 4 pm to 4 am. I work the night shift. I never drink coffee but today I realized that I needed it. My shift includes scientists Paul, Jodi and Darin as well as a survey tech named Vince. We all share staterooms with people who work the opposite shift.

Science Team in Cave — The night shift science team includes Paul, Darin and Jodi (left to right). They monitor the fish in the acoustics lab also known as “The Cave”.

The ocean is very calm but most of us took Bonine (a seasickness medication) anyway to acclimate to the movement. Hopefully we will be adjusted to the motion before the seas get very rough if it does. The rocking of the boat does make one very sleepy.

Cruising the Gulf of Alaska — The sea have been very calm for us.

Did You Know?

The requirements for joining the NOAA Corps include a bachelor’s degree in science, math or engineering and a 5 month program at the US Coast Guard Academy in New London, CT. This is Abby’s second cruise with the NOAA Corps. She has a bachelor’s degree in chemistry and just completed her NOAA officer basic training.

Something to Think About:

What is a day in the life aboard the Oscar Dyson like?