NOAA Teacher at Sea
Aboard NOAA Ship Oscar Dyson
July 22, – August 9, 2013
Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: Wednesday, July 24, 2013
Current Data From Today’s Cruise
Weather Data from the Bridge (6:00 am Alaska Daylight Time)
Sky Condition: Scattered Clouds
Temperature: 12º C
Wind Speed: 12 knots
Barometric Pressure: 1017.2 mb
Sun and Moon Data
Sunrise: 5:40 am
Sunset: 10:38 pm
Moonrise: 10:36 pm (July 23, 2013)
Moonset: 9:11 am
Geographic Coordinates (6:00 am Alaska Daylight Time)
Latitude: 58º 30.5’ N Longitude: 150º 53.9’ W
The ship’s position now can be found by clicking:
Science and Technology Log
This blog is titled Yakutat or Bust because there is a great deal of hope to complete the survey around Yakutat, Alaska in the southeast. On the map below, the green mark is our position in the water near Kodiak Island (the survey actually began a bit west near the islands of Four Mountains) and the red is our final destination of Yakutat Bay. (Photo courtesy of GoogleEarth)
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, a certified sustainable fishery, is processed into fish sticks, fish patties and imitation crab. Last year, about 3 million tons of pollock were caught in the 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, typically pollock grow to about 50 cm and weigh about .75 kg. They live in the water column and feed on small krill, zooplankton, and small fish as they grow. As they age they will eat other pollocks. 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. For example, one of the scientists 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 to Think About:
- 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 and other types of sensors?
- What is a bottom trawl and how is it different from a mid-water trawl?
- What types of careers are available on the Oscar Dyson?
Before we left Kodiak Island on July 22, I was able to spend a day exploring alone and with some of the members of the science team while the crew prepared the ship. The town of Kodiak is one of seven communities on the island and the central location for all commercial transportation on and off the island either by airplane or ferry boat.
Kodiak is the ancestral land of the Sugpiaq, native Alaskans of the Alutiq Nation, who subsisted by hunting, fishing, farming, and gathering. Russian explorers were the first outsiders to visit the island, and under Grigory Shelikof, established a settlement in 1792 that became the center of Russian fur trading. Following the 1867 Alaska Purchase from Russia, the island and the rest of Alaska became the 49th of the United States in 1959. Russian influence is still apparent on Kodiak: the Shelikof Strait separates Kodiak Island from mainland Alaska and the Holy Resurrection Russian Orthodox Cathedral holds a full house on Sunday mornings.
Flora and fauna are abundant in this beautiful location. On a short hike, I was able to sample the delicate salmonberries; fear the beautiful, yet invasive and poisonous hogweed; and watch a gorgeous sunset.
Did You Know?
The background of scientists on the Oscar Dyson varies; however, most have a strong affinity for the ocean and spent a lot of time outdoors exploring nature and playing with various critters as children. Kirsten, for example, is a post-doctoral researcher funded by the National Research Council. She has a BS degree in Marine Biology from Roger Williams University in Rhode Island as well as MS and PhD degrees in Oceanography and Coastal Sciences with a concentration in Fishery Science from Louisiana State University in Baton Rouge. She came aboard the ship to develop a time series of krill distribution in the Gulf of Alaska and to relate that to other species of importance such as pollock.
Something to Think About:
STEM (Science, Technology, Engineering, and Math) are not the only important subjects to know to work on the Oscar Dyson. All three crews on the ship (NOAA Corp, Deck/Fishery Crew, and Scientists) use writing every day. Below are pictures of two log books: one records Weather Data by the NOAA Corp and the other Scientists’ notes.
Alaska’s official flag is based on a design by Benny Benson, a thirteen year old boy. It was submitted in a territory-wide contest for schoolchildren sponsored by the American Legion in 1926. Benny Benson chose the background color of the flag to represent both the blue sky and the forget-me-not. The Alaska legislature later named the forget-me-not as Alaska’s official state flower. The flag inspired the state song, the lyrics of which are seen in the picture below. Marie Drake wrote the lyrics, and Elinor Dusenbury composed the song.