NOAA Ship Oscar Dyson – Page 27 – NOAA Teacher at Sea Blog

July 25, 2009April 6, 2021

Kathryn Lanouette, July 25, 2009

NOAA Teacher at Sea
Kathryn Lanouette
Onboard NOAA Ship Oscar Dyson
July 21-August 7, 2009

Mission: Summer Pollock Survey
Geographical area of cruise: Bering Sea, Alaska
Date: July 25, 2009

Weather Data from the Ship’s Bridge
Visibility: 10+ miles (to the horizon)
Wind direction: 030 degrees (NE)
Wind speed: 15 knots
Sea wave height: 4-6 feet
Air temperature: 6˚C
Seawater temperature: 6.4˚C
Sea level pressure: 29.85 inches Hg and rising
Cloud cover: 8/ 8, stratus

Science Log

Why study walleye pollock? Before even setting sail, I wondered why NOAA scientists were interested in studying walleye pollock. It turns out that walleye pollock is the largest fishery, by volume, in the USA. In one year, about 1 million metric tons of walleye pollock are fished, mostly from the waters of the Bering Sea. Given that walleye pollock accounts for such a large percentage of the total fish caught in the United States, I was curious why I had never seen it on restaurant menus or rarely seen it at supermarket fish counters. It is because walleye pollock is usually processed into other things – like fish sticks, imitation crabmeat, and McDonald’s fish fillet sandwiches. So it seems that walleye pollock is that mild white fish you often eat when you don’t know for sure what kind of fish you are eating.

Above is a map showing the 31 transect lines of the walleye pollock survey area. I have joined the cruise that is sailing along the 8 transect lines closest to Russia.

In addition to supporting a major multi-billion-dollar fishing industry, walleye pollock is a fundamental species in the Bering Sea food web. It is an important food source for Steller sea lions as well a variety of other marine mammals, birds, and fish. The population size, age composition, and geographic distribution of walleye pollock significantly affect the entire Bering Sea ecosystem. What do scientists hope to learn about walleye pollock? NOAA scientists are primarily interested in calculating the total biomass of walleye pollock. To estimate how many walleye pollock are in the Bering Sea, scientists sample the fish, recording their age, length, weight, male/female ratio, and geographic location. This information is used by North Pacific Fishery Management Council (NPFMC) to set sustainable fishing quotas for the following year. The NPFMC, whose membership comprises university, commercial, and government representatives, uses NOAA’s survey data, fishery observer program data, as well as catch statistics from the commercial fishing industry, to determine how much walleye pollock can be fished in the coming year.

An illustration of the Oscar Dyson sending down sound waves (in order to “see” the animals swimming below the water’s surface.)

Where do scientists study walleye pollock? Every year or two, a NOAA research ship (usually the Oscar Dyson) travels throughout the Bering Sea, following approximately 31 transect lines. These transect lines can be anywhere from 60 to 270 miles long. These lines were selected because they include areas where either walleye pollock spawn in the winter or feed in the summer. As the ship travels along these lines, its sonar system uses sound waves to locate fish and other animals living below the water’s surface. As the sound waves return to the ship, they create different images, depending on which animals are swimming in the water below. Using these images, the scientists decide whether or not they should lower the nets and sample the walleye pollock. They also continuously store digital data from the images, later using this information to estimate the total biomass of the fish species. On this 18 day research cruise, the scientists are hoping to travel the last 8 transect lines (over 1,500 nautical miles). Each transect line takes us into Russian waters. On Thursday, we reached our first transect line. Within hours of traveling along this first line, many schools of walleye pollock were spotted. After the fish net was brought up, I was amazed at the number of fish that came sliding down the conveyor belt into the science lab. I helped weigh and measure hundreds of fish, a quick introduction to the whole process!

Personal Log

We traveled into Russian waters today, crossing the International Date Line as we went. So technically, Saturday became Sunday this afternoon! But later in the evening, we completed the transect line, turned, and headed back into Saturday just as night fell. Luckily, the time never changes here on the boat. The scientists and crew live on Alaska Daylight Time (ADT), regardless of how far we travel to the north and west. I’ve see a few whales spouting but so far, I haven’t been able to identify any. In the coming days, I am hoping to get a glimpse of their backs or flukes (tails). It has been exciting seeing so many animals – some of which I never even knew existed. A few of these animals look a bit scary, like this Pacific lamprey. Its mouth forms a suction and then all those small yellow teeth go to town, letting it feed on the blood and tissue of its prey. Even the small tongue in the back of its mouth is toothed!

Animals Seen
Hyperiid amphipod Aequorea species, Chrysaora melanaster jellyfish, Euphausiids (aka krill), Pacific lamprey, and Short-tailed albatross.

New Vocabulary: Biomass – the total amount of a species, by weight Cruise – nautical trip, for science research or fun. Quotas – a limited or fixed number or amount of things. Sample – to study a small number of species from a bigger group. Transect Line – a straight line or narrow section of land or water, along which observations and measurements are made

Question of the Day
Why are only some jellyfish species capable of stinging?

Here I am holding up a Chrysaora melanaster jelly fish (Luckily this species doesn’t sting!) — Holding up a Chrysaora melanaster jelly fish (Luckily this species doesn’t sting!)

July 22, 2009April 6, 2021

Kathryn Lanouette, July 22, 2009

NOAA Teacher at Sea
Kathryn Lanouette
Onboard NOAA Ship Oscar Dyson
July 21-August 7, 2009

Mission: Summer Pollock Survey
Geographical area of cruise: Alaska
Date: July 22, 2009

Weather Data from the Ship’s Bridge
Visibility: 3 nautical miles
Wind direction: 288.27 degree (N, NW)
Wind speed: 20 knots
Sea wave height: 8-10 feet
Air temperature: 7.4 ˚C
Seawater temperature: 6.8 ˚C
Sea level pressure: 29.3 inches Hg and rising
Cloud cover: 8/ 8, stratus

Science and Technology Log

It will take about 2 ½ days of non-stop sailing until we reach the fish survey starting area. Before that research gets underway, I’ve been spending a lot of time getting to know my way around the ship and learning about life at sea. My favorite part of the ship to spend time has been the bridge, the navigation and operations base for the entire ship. From the bridge, I’ve been able to learn more about the weather and birds that live at sea. Every hour, the weather is recorded using the boat’s instruments. This weather is then relayed to NOAA’s National Weather Service. Using the Oscar Dyson’s data, the National Weather Service is better able to predict and model weather patterns, increasing their forecast’s accuracy for this remote region. As the waves kicked up a lot on Tuesday evening, I learned about the Beaufort Scale of Wind Force.

Using estimated wave speed and wave height, you can calculate the severity of the weather. On Tuesday evening, we were sailing through a Force 7 on the scale, a gale with wave heights of 13.5 to 19 feet and a wind speed of 28-33 knots (aprox. 35-37 mph) with gusts up to 45 knots (aprox. 50 mph) Luckily, the waves have calmed down a lot by Wednesday evening because the lower pressure system has passed us to the east.

A Northern Fulmar (Courtesy Aaron Lang, USFWS)

In addition to fisheries research, there are two bird observers from the U.S. Fish and Wildlife Service (USFWS). For almost 16 hours each day, they observe and record information about the seabirds that they see flying within 300 m of the boat. Seabirds spend most of their lives living out on the open seas, looking for food. A lot is known about their cliff nesting areas by the water because these locations are relatively easier to access. Much less is known about their time spent at sea. The information gathered here helps scientists learn more about the birds that inhabit the Bering Sea. By looking at their data from prior years, they can sea how different birds are affected by human caused events (like oil spills, global warming, and commercial fishing) and non-human caused events like volcanic eruptions. All their research is part a bigger research program called the Bering Sea Integrated Ecosystem Research Program (BSIERP). As one seabird was flying close to the boat, I noticed it had a slender tube on top of its bill. It turns out that this bird was a Northern Fulmar, part of a group of birds called “tube-noses.” This tube enables the birds to drink saltwater, a cool adaptation to life at sea.

Here I am practicing wearing my immersion suit.

Personal Log

On Tuesday afternoon, as we left the protected bay of Dutch Harbor, we started sailing out towards the more open waters of the Bering Sea. It was a strange feeling to see the Fox Islands, a smaller part of the Aleutian Island chain, slipping out of sight. Our next chance of seeing land will be as we get closer to Russia. Even then, it might be too cloudy. It is strange to think that I might not see land again for over two weeks. By 9pm on Tuesday night, I was sick as a dog, “hanging over the rails” if you will. But with some sleep and seasickness medicine, I am feeling a lot better today. Seems I have found my “sea legs” as food seems appealing once more and the boats rocking is becoming more of a lulling motion than a lurching one. Around noon on Wednesday, we had our first fire drill and abandon ship drill. As part of the drills, we had to practice putting on our immersion suits. In case we had to abandon ship for any reason, these suits would keep us warmer and more visible. I felt a bit like Gumby!

Animals Seen
Northern Fulmar Black Legged Kittiwake Tufted Puffin Horned Puffin Black-Footed Albatross Laysan Albatross Murre

New Vocabulary
Knots – units of speed, nautical miles per hour Nautical mile – 1.15 statute (regular) mile

July 16, 2009April 5, 2021

Megan Woodward, July 16, 2009

NOAA Teacher at Sea
Megan Woodward
Onboard NOAA Ship Oscar Dyson
July 1 – 18, 2009

Mission: Bering Sea Acoustic Trawl Survey
Geographical Area: Bering Sea/Dutch Harbor
Date: Tuesday, July 16, 2009

All bony fish have otoliths (ear bones) that can be used for calculating the age of the fish.

Weather and Location
Position: N 58 13.617; W 171 25.832
Air Temp: 7.2 (deg C)
Water Temp: 6.54 (deg C)
Wind Speed: 15 knots
Weather: Overcast

Science and Technology Log

One of the most interesting things I’ve learned while participating in the pollock survey is the importance of otoliths. Otoliths are small bony structures situated in the head of all bony fish, and are often referred to as “ear stones.” For each haul we brought on board, 50 otoliths were taken from large fish (3+ years) and/or 5 from small fish (younger than 3 years old). The otolith holds the key to accurately calculating the age of a fish (scales and vertebrates can also be used, but are not as reliable). The average age of fish from the samples collected in the survey helps scientists estimate the strength of a year-class and size of the stock in the future.

Back in the lab, otolith samples are carefully catalogued.

The first step in taking an otolith is pictured above. An incision is made on the back of the pollock’s head, and an otolith is removed using tweezers. Once the otolith is removed, it is rinsed with water and placed in a glass vial containing a small amount of 50% ethanol solution for preservation purposes.

The otoliths are taken back to NOAA’s aging lab where ages are determined by reading rings similar to those on a tree trunk. A crosscut is made through each otolith revealing a pattern of rings. Scientists then count the rings to determine the age of the fish. Lightly burning or staining the otoliths makes the rings more visible.

New material is deposited on the surface of the otolith creating the rings as the fish grows. The translucent/light zones indicate the main growth that takes place in the summer months. The opaque/darker rings appear during the winter months when growth is slower. Because of the slower growth rate, new material is deposited on top of the old layers resulting in the dark ring. Each pair of light and dark zones marks one year. In fish younger than one year of age, rings can be identified for each day of life!

Personal Log

I was surprised to discover otoliths have been used for aging fish since the early 1900’s. While working in the fish lab I observed the scientist removing otoliths, however I did not remove any myself. The cracking sound heard when cutting the head open was like fingernails on a chalkboard to me. I spent most of my time in sorting and measuring fish, as well as assisting with the stomach collection project.

For the next two days we will be heading back to Dutch Harbor, and the likelihood of trawling for more fish is minimal. Our remaining work assignment is to give the fish lab a thorough cleaning. Everything in the lab is waterproof, so we’ll put on our Grunden’s (orange rubber coveralls) and boots and spray down the entire space. Working and living at sea for nearly 3 weeks has been an eye opening experience. My time aboard the Oscar Dyson has flown by. I have learned so much about fisheries research and life at sea. Dry land, however, will be warmly welcomed when we get back to Dutch Harbor. Would I do it again? Absolutely.

Animal Sightings

The whales have an incredible way of showing up when I don’t have my camera. Yesterday I spotted two orcas, but did not get a photograph. The seabirds continue to circle. I like the murres most. They look like small, flying penguins.

New Vocabulary

Otoliths- Small bony structures situated in the head of all bony fish. Often referred to as “ear stones.”

Stock- Refers to the number of fish available, supply.

*** Much of the information used for this log entry was found on the Centre for Environment, Fisheries & Aquaculture Science (Cefas) web site.

July 12, 2009April 5, 2021

Megan Woodward, July 12, 2009

NOAA Teacher at Sea
Megan Woodward
Onboard NOAA Ship Oscar Dyson
July 1 – 18, 2009

Mission: Bering Sea Acoustic Trawl Survey
Geographical Area: Bering Sea/Dutch Harbor
Date: Tuesday, July 12, 2009

Any bycatch in a haul has to be measured and weighed if there are more than 25 of the same species caught. — Any bycatch in a haul has to be measured and weighed if there are more than 25 of the same species.

Weather/Location
Position: N 60.35.172; W 174.08.187
Air Temp: 6.1 (deg C)
Water Temp: 5.24 (deg C)
Wind Speed: 25 knots
Weather: Overcast, rain

Science and Technology Log

How is all the data collected from a trawl and acoustic lab used? By collecting data about weight and length from a sample, scientists are able to connect the size of fish caught to the amount of return seen in the acoustic lab. The return is assigned a name (PK1, PK2, etc.) and all schools showing a similar acoustic pattern are given the same name. In the end, scientists can estimate the number of fish and their size for a given area based on the acoustic and fish lab data collected. This is repeated throughout the survey resulting in an estimate for the total number of fish in the survey area.

Both during and after the survey estimates of abundance in the same location over the past several years are compared. Scientists evaluate the data and determine if the pollock population in the survey area is increasing, declining or stable. Their conclusions are used to make a recommendation about pollock fishing limits for the upcoming year. In the past few years the pollock population has been lower than in previous years. Due to the decline, the fishing quota has been reduced. However, the 2006 year-class is proving to be strong. At 4 years of age pollock are considered mature and fishable. Therefore, the fishing quota is predicted to rise in the next year or two.

Personal Log

While discussing the acoustic survey project with the scientists on board, I was quite surprised to hear the pollock survey had been going since 1979. Acoustic technology has changed and improved, but in essence the project has remained the same. Modern computer technology has allowed collection and analysis of enormous data sets and greatly reduced the amount of paper work needed for the project’s success.

The concept of strong vs. weak year-class is also quite interesting. There doesn’t seem to be a direct connection between a year-class’ success and environmental factors. Environmental factors that are potentially influential are water temperature, available zooplankton, ice cover, storms and predators. The fish currently being caught by commercial fisherman are 5-7 years old. Can you figure out which year classes those fish are from?

We continue to spot plenty of seabirds and a few more minke whale pods. I was able to watch a group of Dall’s porpoises play in the wake of the bow for half an hour yesterday. There haven’t been any new animal sightings during the past few days.

Although we are out here working in the best interest of pollock, I have found it difficult to watch thousands of pollock come through the fish lab. I have to remind myself that sampling the fish is truly for the good of the order. In addition, after being measured the fish are sent back into the ocean where they become food for other organisms such as crab or birds. One of their natural predators is having a good meal, something that was likely to happen anyway.

Animal Sightings

Seabirds
Dall’s porpoises

New Vocabulary

Bycatch – Anytime something is caught during a trawl other than pollock it is labeled bycatch. Jellyfish has been the most common form of bycatch.

Year-class – All the fish born in a given year are members of that year-class. We have caught a lot fish from the 2008 year-class (1 year old fish).

July 10, 2009April 5, 2021

Megan Woodward, July 10, 2009

NOAA Teacher at Sea
Megan Woodward
Onboard NOAA Ship Oscar Dyson
July 1 – 18, 2009

Mission: Bering Sea Acoustic Trawl Survey
Geographical Area: Bering Sea/Dutch Harbor
Date: Tuesday, July 10, 2009

The pollock are carefully loaded onto the table.

Weather/Location
Position: N 56.30.202; W 172.34.37
Air Temp: 7.4 (deg C)
Water Temp: 7.4 (deg C)
Wind Speed: 19 knots
Weather: Overcast

Science and Technology

Once the fish are onboard a rigorous data collection process begins. All of the data collected are recorded via instruments linked to a computer network in the fish lab. Below is a series of photos showing the process used in the fish lab to collect valuable data.

Once the fish are on the table, we carefully look through the fish for any species other than pollock caught in the trawl. These non-pollock species are sorted into bins and accounted for. The fish are weighed one basket full at a time as they reach the end of the conveyor belt. Initially, we take a count of how many fish fill one basket. There is a scale connected to a computer program that records the basket’s weight.

The sorting begins. The pollock are sorted between male and female.

After weighing the pollock, we move on to sorting a sample of approximately 300 fish by sex. To find the sex of a fish we cut open its belly and look for either male or female reproductive organs. The sexed fish are then placed in the appropriate bin. Next, each pollock from the male/female sort is measured in centimeters. We use a measuring board linked to a computer that records the size of each fish. There is a small tool in my hand that gets placed at the “v” of the fish tail. Sensors on the board detect the placement of the measuring wand, and send a length measurement to the computer so it can be recorded. This program also keeps track of how many fish we measure, so we get an accurate sample count.

The stomach of a pollock is prepared for preservation.

Several scientists have asked us to collect pollock for various research projects. One project, designed to study the diet of pollock, requires us to sex, measure, weigh and take the stomach of 20 pollock from each haul. A label with all of the information is placed in a bag with the stomach. They are placed in a freezer for preservation purposes.

Here I am using the measuring board. The stomach of a pollock is prepared for preservation. — Here I am using the measuring board.

We also use a similar process for scientists examining one-year-old pollock. This study asks for the entire fish to be preserved, not a specific organ. In one 12-hour shift there is a maximum of 3 trawls if fish sign is identified in the acoustics lab. Each trawl takes 2 to 3 hours to process. It’s possible another trawl could happen while finishing up the data collection from the previous haul. This makes for a very busy, fish filled shift.

Personal Log

Working in the fish lab has provided for a tremendous amount of new learning to take place. I’ve learned to identify species of fish that mix in with pollock (capelin, flatfish, skate and cod), and have seen several crustaceans and jellyfish, too. All of the measuring technology has been straight forward and user friendly. Sexing the fish has been the most difficult job, but has become easier with practice. Examining the innards to identify male or female reproductive organs seems nearly impossible in the young fish, and it’s not always clear in the older fish.

Today I was in charge of weighing the fish as they came down the conveyor belt. I was certainly mistaken when I thought it would be a simple task. First off, I had to count the fish as they dropped into the basket at a speed faster than I could count. At the same time I had to control the speed of the belt and open the gate so more fish would move down the line. When the basket was full, I stopped the belt and placed the full (semi-accurately counted) basket on the scale and waited for the scale’s “steady” signal to come on. Since the boat is constantly in motion the steady light rapidly blinks on and off. It took me three tries before I managed to get the basket weighed. Meanwhile the rest of the team patiently waited. Maybe I’ll give it another try tomorrow.

This average sized skate was flapping his wings making him difficult to hold. Look closely at the fish on the conveyor belt and you will see hermit crabs and seastars.

Basketstars were brought up in a bottom trawl. Hermit crabs and snails were also caught in the bottom trawl. — Basketstars were brought up in a bottom trawl.

Hermit crabs and snails were also caught in the bottom trawl. — Hermit crabs and snails were also caught in the trawl.

Animals Seen

Minke Whale
Skate
Pacific Cod
Tanner Crab
Snow Crab
Basketstar
Sturgeon Poacher
Snails
Hermit Crabs
Arrow Tooth Flounder