Modeling the role of menhaden as forage and filter feeders

Project Title: Modeling Atlantic menhaden in support of nutrient and multispecies management
Principal Investigators
Dr. Mark Brush
Dr. Rob Latour
Dr. Liz Canuel
Project period: 8/16/05-8/15/08
Funding Agency: Chesapeake Bay Program (US EPA)

Menhaden (Brevoortia tyrannus) play an important ecological role in Chesapeake Bay both as prey for large predators such as striped bass and as filter feeders that can potentially help clear nutrient-polluted Bay waters.

The goal of this project is to quantify the role of menhaden in these two areas.

We will do so by coupling a baywide assessment of the menhaden stock with a detailed experimental study of menhaden diet and feeding behavior to fill critical gaps in our knowledge. We will use these results to model the bioenergetics of menhaden on both the individual and population level. We will then couple this bioenergetics model to a nutrient-plankton and multi-species predator model both separately and in combination. These models will be used along with the NOAA Chesapeake Bay Ecopath model to assess how different population levels of menhaden might affect Bay water quality and how different nutrient-reduction and fishery-management scenarios might impact the menhaden population and its potential to improve water quality. Our results will thus provide the basis for weighing potential management options. Results will also be used to fully develop the menhaden component of the Ecopath model.

We will perform all stock assessments, experimental work, initial consumption estimates, model construction, and initial simulations in Year 1. In Year 2, we will complete the experiments and use the results to fully calibrate the models and complete all menhaden-based modeling activities. We will incorporate oysters and fully develop zooplankton in our models in Year 3 using results of current CBP-funded projects on these organisms. Simulations of this integrative model will allow comparison of the major filter feeders in the bay, their potential to affect water quality, and interactions among these filter feeders, water quality, and fish predators.