R/CR-1

Description:

Objectives: (1) Based upon laboratory experiments, test multivariable effects of temperature, salinity, and dissolved oxygen on principal bioenergetic responses of juvenile white perch. (2) Parameterize a bioenergetic model for white perch juveniles. (3) In measocosm trials, test the bioenergetic model. (4) (Contingent upon renewal). Using 17 years of Chesapeake Bay Program water quality data, map and analyze past effects of water quality on the potential production of white perch, and evaluate possible scenarios of future changes in temperature and dissolved oxygen. Methodology: We will construct a multi-variable eco-physiological framework, emulating one recently developed for sturgeons, which uses a semi-balanced oxygen budget. Growth, food consumption, routine metabolism, feeding metabolism and excretion rates of juvenile white perch will be measured in the laboratory. The experimental design will evaluate functional responses to main effects and first order interactions between water quality parameters. Treatment levels will emulate those that occur in the Bay. The bioenergetic model will be supplied with bottom water quality data from the Chesapeake Bay Monitoring Program, to map and analyze past and future changes in white perch carrying capacity. Rationale: We propose a deductive approach to engage the question, how do we expect the production of living resources to be affected by ecosystem-level changes in water quality? It is increasingly apparent that water quality parameters interact, and are nonlinear in their effects on fish production. Current bioenergetic models are insufficient in design and application to accommodate these effects. Further, the Chesapeake Bay represents a unique system to apply spatially explicit bioenergetic modeling because we can supply models with over 15 years of intensive water quality data. We have already developed this approach to Chesapeake sturgeons. Now we request funding to develop and apply this approach to a dominant and well-studied component of the Chesapeake Bay's fish community: white perch