GLOBEC 2000: Responses of the Neocalanus spp. - Microplankton Community to Physical Forcing in the Coastal Gulf of Alaska

Louisiana Universities Marine Consortium, Chauvin LA

Investigators

Abstract

The investigators will examine processes structuring microplankton communities and linking them with populations of Neocalanus spp., the dominant particle-grazing copepods in the coastal Gulf of Alaska. Collectively, three species of Neocalanus contribute substantially to total spring and summer mesozooplankton biomass in the coastal Gulf of Alaksa. Neocalanus are capable of consuming both phytoplankton and microzooplankton, though factors dictating this diet partitioning are not well understood. Further, these copepods have been shown to alter individual body size, population biomass, and life cycle timing in response to variations in ocean conditions. Finally, the size and abundance of Neocalanus make them an important potential prey for pink salmon fry and other coastal fish species. Thus, the microplankton - Neocalanus food web is a potential locus for the translation of environmental variation into higher trophic level responses. Specific measurements to be made include: microplankton abundance and composition, rates of microzooplankton herbivory, and rates of Neocalanus spp. grazing on microzooplankton and phytoplankton.