NOAA Teacher at Sea
Aboard NOAA Ship Oscar Dyson
July 5 – 25, 2015
Mission: Walleye Pollock Survey
Geographical area of cruise: Gulf of Alaska
Date: July 7, 2015
Weather Data from the Bridge:
Latitude: 56 36.1N
Longitude: 156 04.1W
Speed: 12 knots
Wind Speed: 4 knots
Wind Direction: 202 degrees
Surface Water Salinity:35.31
Air Temperature: 12.6 C
Barometric Pressure: 1004.6 mbar
Sky: SCT (scattered clouds)
Science and Technology Log:
The walleye pollock fishing industry is the largest commercial fishing industry in the country, and one of the largest fishing industries in the world. Have you eaten fish sticks? Filet-O-Fish from McDonald’s? Imitation crab? If your answer is yes to any of these questions, then you have eaten walleye pollock. Since pollock supports such a large industry, scientists need to carefully monitor its abundance each year. Bring on the scientists and crew on board the Oscar Dyson to make this mission possible.
TIn summer, and in a few locations in winter, scientists head out to assess the walleye pollock population in both the Bering Sea and in the Gulf of Alaska. The summer survey alternates between the two areas, and this summer we are traveling in the Gulf of Alaska for our survey. This second leg (out of 3 legs total) will head counterclockwise around the island of Kodiak. This survey, conducted by the Midwater Assessment and Conservation Engineering Program at the Alaska Fisheries Science Center in Seattle, uses acoustic technology to gather data on the distribution and abundance of fish, which provides researchers with pertinent information about the walleye pollock population.
The Oscar Dyson is a relatively new ship, equipped with noise quieting technology in order to create as little acoustic disturbance as possible when out at sea. Another neat feature crucial to the work of the Dyson is the acoustic transducers located on the bottom of the ship. There are several of these transducers, which are composed of small ceramic disks, and they help scientists detect ocean life and map the seafloor. If you are like me, you are probably wondering what a transducer is, right? It took me a couple of explanations and analogies in order to understand what was happening in these tiny devices. Remember, sound waves are pressure waves that move through a medium, in this case water. The transducer converts electrical energy to mechanical energy, expanding and contracting with electrical signal it receives. This expansion and contraction creates sound waves that move through the water away from the transducers. After sending the pressure waves the transducer switches modes to “listen” to the incoming waves. When the sound waves hit something in the water they are reflected back to the transducer. These reflected waves that are received by the transducers indicate the presence of obstacles in the water. An analogy for this process is that the transducer first acts as a speaker and then as a microphone.
Five of these transducers are being used for the pollock survey in order to detect pollock and other ocean life. The information the transducer receives back is automatically graphed on the computer. Scientists and other crew members can view and analyze this graph, and will use this information to determine when it is appropriate to send out a trawl to collect fish. There are also several transducers located around the bottom of the ship that are gathering information about the ocean floor. Hydrographic surveys use this technology as they map the sea floor. I am amazed at where we have come with technology, especially out at sea. Stay tuned for my next post to learn about more amazing technology we are using on board!
Lucky. That is how I would describe myself when I landed at the Kodiak airport on my flight from Anchorage. First, I was lucky that the flight I was scheduled on made it to Kodiak on its first attempt, as flights are often cancelled for poor weather or low visibility. Planes have been known to turn around and fly back to Anchorage if they can’t make a safe landing in Kodiak. I am also feeling very lucky to have the opportunity to partake in yet another assignment as a NOAA Teacher at Sea, in another area of the country I haven’t yet explored.
I arrived in Kodiak on the 4th of July, and was swept up from the airport by one of the NOAA Corps officers, ENS Justin Boeck. We weren’t scheduled to depart on the Oscar Dyson until Monday, July 6th, so Justin gave me a quick tour of the ship. I wasn’t sure what to expect of the Oscar Dyson, but when my first thoughts climbing on board were that it would take me a week to find my way around! It is much larger than the last ship I was on, the Oregon II, down in the Gulf of Mexico.
Trying to take advantage of the nice weather, I decided to explore the area before we left. The town of Kodiak is quaint, and in walking through the downtown area, it is clear that fishing has been and will continue to be integral to the way of life here.
The science crew came in on the 4th as well from Seattle. I met them all when we went out to dinner Saturday evening. Even though we are going to be sleeping on the ship for next 2 nights before we depart, meals won’t be served until we are underway. I did manage to track down some good sushi and seafood places here in town, and am quite satisfied!
On Sunday, the weather turned for the worse, which made the walk into town for coffee a wet one. If you think weather changes quickly in Colorado, try coming to Alaska. My favorite image of the weather status was at a little shop in Homer, Alaska, which outlined a box with a marker on the window and wrote, “If you want to know the weather, look here.”
That afternoon, I was given a little orientation on what some of my tasks would be on the ship, as there is quite a bit going on in addition to the pollock survey. I will be spending most of my time in the acoustics lab analyzing data, the wet lab processing our catches, and chem lab for some of the special projects.
In the evening, the weather cleared just long enough for me to convince ENS Gilman (ok, he didn’t really need any convincing- he was just as excited as I was) to head down to the pier to test out the Waverunner, the ROV made by the students in my class. While the visibility was not the best, we were able to see plenty of moon jellies, sea anemones and some kelp beds. The ROV handled pretty well in the ocean, although we did have some difficulties bringing it back up when it went down too deep. Students, do you have any suggestions for how we could account for this? Any suggestions or modifications we need to make?
We were supposed to be leaving early afternoon on Monday, however due to the bad weather, several of our crew members had not yet made it in to Kodiak. They finally made it over later that afternoon and we left port at 11pm. I stayed up to watch the sun set as we were leaving port (yes, it does actually set in parts of Alaska), and pushed myself to stay awake for a few more hours. I’ll be working the night shift for the next few weeks, which means I’m on duty from 4pm-4am. The faster I can get myself used to this schedule, the better off I’ll be. The first days in Kodiak have been a blast, and I am excited to begin conducting our survey!
Did you know? Acoustic transducer technology has been in use since World War II.
Where on the ship is Wilson?
Wilson, our ring tail camo shark (so aptly named by our awesome science crew) , has been enjoying his time on the ship as much as I have. He has traveled all over the place, and is having fun with the crew on board. Can you guess where he is in the picture above?