Alaska Physical And Oceanographic Research

Physical and oceanographic conditions affect where fish and crab species spawn, feed and develop. This information has important implications for future fish and crab population size.

Alaska

Scientific equipment used to get samples from the ocean

Ecosystem Monitoring and Assessment Program staff member inoculates phytoplankton samples.

We investigate various physical and biological parameters in the eastern Bering Sea. Spatial and temporal patterns illustrated by these data provide critical insight into how the ecosystem functions.Oceanographic data are analyzed alone and in conjunction with fisheries data for comparisons of water mass characteristics. Water samples collected above and below the pycnocline are analyzed for chlorophyll a concentration to explore productivity and are used in primary production experiments to explore fish and crab species growth rates. Phytoplankton form the base of the food web and perform a critical role in the Bering Sea ecosystem.

Oceanographic CTD retrieval.

Zooplankton and jellyfish are collected for species ID, biomass, and abundance. Zooplankton are an important prey item of numerous Bering Sea fish including forage fish (i.e., herring and salmon) and the juvenile stages of many commercially important species. Understanding the links among phytoplankton, zooplankton, and fish will further our understanding of changes in fish populations and the influence of climate change in this region.

Oceanographic Collections in the Bering Sea Include

Physical and Chemical Data collected via CTD and TSG
Temperature
Conductivity
Salinity
Density
Light Transmission
Photosynthetically available radiation (PAR)
Oxygen
Chlorophyll a

Biological Data Includes

Phytoplankton (for discrete analysis of chlorophyll a and primary production experiments using stable isotopes of carbon and nitrogen)
Zooplankton
Jellyfish
Primary Production experiments for uptake rates of various nutrients