GLOBEC 2000: Mesoscale surveys in the Gulf of Alaska: microplankton
(E. Lessard [University of Washington])
This is one of three collaborative GLOBEC proposals for mesoscale surveys to study the physical and biological processes controlling the growth and survival of juvenile pink salmon on the Gulf of Alaska shelf. A central objective of the mesoscale studies is to determine how physical forcing affects the availability and production of zooplankton prey for juvenile pink salmon. Juvenile salmon prey (copepods, euphausiids, pteropods, amphipods) depend directly or indirectly on diverse microplanktonic prey, including microzooplankton (flagellates and ciliates) which have recently been recognized to be a significant dietary component of zooplankton. The size-structure, taxonomic composition and growth dynamics of the lower trophic food web are expected to be highly responsive to physical forcing and, in turn, exert strong influences on zooplankton growth, fecundity, community composition and nutritional state. The focus of this proposal is to describe quantitatively the abundance, biomass and size-structure of the microplankton (phytoplankton and microzooplankton <200m) prey fields. Group-specific phytoplankton growth and microzooplankton grazing rates will also be measured to identify trophic pathways and responses to changing physical regimes. This study will provide critical mechanistic insight and validation for coupled biological-physical models of the Gulf of Alaska shelf ecosystem.
This page was last updated on September 22, 2000.
Maintained by:
Hal Batchelder [hbatchelder@coas.oregonstate.edu
College of Oceanic & Atmospheric Sciences
Oregon State University
Corvallis, OR 97331-5503
phone: 541-737-4500; FAX 541-737-2064