9504081 Monismith This proposal will link hydrodynamics, the ecology and behavior of siphonate benthic infauna, and phytoplankton dynamics. The ultimate objective is to quantitatively predict when phytoplankton biomass can be controlled by these benthic organisms. The research will employ two closely related and complementary studies: laboratory work with mechanical models of siphonate bivalves and with live animals, and computational work using two coupled hydrodynamic-phytoplankton codes. The research will be supported by field work carried out as part of the ongoing United States Geological Survey studies of San Francisco Bay. The laboratory studies will invoke two elements: turbulent and scalar mixing over a model bivalve bed and assessing the extent to which bivalve behavior (feeding strategies and densities of feeding animals) alters the results obtained with mechanical analogs. The modeling studies will include the application of two coupled hydrodynamic- biological models to study the effects of vertical and horizontal mixing on phytoplankton production and consumption in shallow estuarine and coastal systems.
