Wyatt's letter, answered by Jay Clark, a Research Biologist at the NOAA Alaska Fisheries Science Center (AFSC) in Seattle

Greetings Wyatt -
    My name is Jay Clark and I am a research biologist with the NOAA Alaska Fisheries Science Center in Seattle. I am with the Recruitment Processes division, which is a part of the FOCI program. Our group collects and studies fish larvae, fish eggs, zooplankton and juvenile fish. We use a variety of plankton nets to collect our samples. Some of the nets we use are: Bongo nets, Tucker trawl, Neuston, epibenthic sled, Methot, and MOCNESS. All of these nets have been used on the Oscar Dyson.
    The CTD (which stands for Conductivity, Temperature and Density) gives us an immediate profile of the water column on a graph so the scientist can see where the salinty and temperature change at any given depth. We also have water bottles that go down with the CTD, which are opened and closed at whatever depths we chose. So, we can sample things such as nutrients, chlorophyll, oxygen at the depths we are interested in.
    As far as the population of pollock, there are several factors that go into estimating the number of adult fish. In FOCI, we collect pollock eggs and larvae in the spring. Another group uses acoustic sonar to estimate the size of schools of pollock. And there is also a trawl survey that catches adult fish to determine the size, age, sex and spawning condition. Information from the commercial fisherman is also important. All of this information is used by the experts to get an estimate of how the health of the pollock population is doing.
    Good luck in your studies.
        Jay