Coupling Water Quality and Upper Tropic Level Modeling for Chesapeake Bay

The Chesapeake Bay Program has invested in several numerical models to address issues related to management of the estuary. The Chesapeake Bay Water Quality Model (CBWQM) has been the primary tool used to forecast estuarine ecosystem responses to variations in nutrient and sediment inputs from the watershed. Although this model includes variables related to food supply at lower trophic levels (plankton, benthos) and related to benthic habitat conditions (O2, SAV), it does not simulate dynamics of exploited fisheries populations. Many of the goals of the Chesapeake 2000 agreement relate to interactions between water and habitat quality and populations at upper trophic levels. This workshop helped us address the following goals: to assess capabilities and limitations of CBWQM and Ecopath with Ecosim for addressing interactions between water quality, habitat condition, food availability, and fisheries population dynamics; to identify possible mechanisms by which these two models could interact via direct or indirect coupling; and to consider alternative modeling approaches for simulating dynamic interactions between exploited animal populations and the ecosystems that they inhabit. The workshop discussions led to several tentative conclusions regarding model coupling and recommendations for future action.