Phytoplankton standing stocks are potentially influenced by both the supply of nutrients to the bottom of the food web and removal by suspension feeders higher in the food web. Similarly, suspended sediment concentrations are determined by both their loading rates and their removal or settlement from the water column. Most management activities to date have addressed the supply end of these relationships by attempting to reduce nutrient and sediment loading to waters within the Chesapeake Bay watershed. However, to predict the relationship between nutrient or sediment loading and water quality,

it is also important to understand and predict the potential top-down effect of suspension feeders such as menhaden, zooplankton, bivalves and other benthic invertebrates on phytoplankton and suspended sediment. These suspension feeders remove particles from the water column and potentially influence nutrient cycling, water clarity, phytoplankton dynamics, and other ecosystem processes. The impact of suspension feeders depends on population levels and distributions of the various species, which, in turn, can be influenced by both management actions and natural variation in physical and biological factors. The current Chesapeake Bay Agreement includes the commitment: "By 2004 assess the effects of different population levels of filter feeders such as menhaden, oysters and clams on Bay water quality and habitat.," The ‘Suspension Feeders Workshop’ is a response to this commitment. Its goals are 1) to assess current understanding of the biological and physical characteristics of the Chesapeake ecosystem needed to estimate suspension feeder effects, 2) to assess the utility of currently existing models, and 3) to identify critical features (processes, organisms, model capabilities) to include in future models designed to predict effects of suspension feeders on phytoplankton and sediment in Bay waters. The workshop will include plenary presentations and discussions, and three concurrent breakout groups - one each on menhaden, benthic suspension feeders (including oysters), and zooplankton. A workshop report will summarize plenary and breakout group discussions, and outline steps recommended to meet the filter feeder commitment.

Meeting Materials and Supporting Documents

Invitation
Overview and Objectives
Agenda
Presentation Abstracts
Questions to Consider to Meet C2K Goals
Workshop Participants

Ecosystem Processes and Higher Trophic Levels

Review of the Benthic Process Model with Recommendations for Future Modeling Efforts
(Executive Summary)

Development of a Suspension Feeding and Deposit Feeding Benthos Model for Chesapeake Bay

Defining the "Filter-Feeder" Commitment of the Bay Agreement


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