An ecosystem-based modeling approach: The Chesapeake Atlantis Model

The Chesapeake Atlantis Model (CAM) is a true ecosystem-based model for fisheries of the Chesapeake Bay, and a tool for management strategy evaluation (MSE).  CAM incorporates spatially-explicit information about the biological, geochemical, and physical factors that drive the ecosystem of the Bay.  CAM can be used to investigate the probable effects of a wide variety of change to Bay resources in an ecosystem context, whether the change concerns user groups (e.g., fisheries, land development, industry), management strategies (e.g., catch shares, closed areas, restoration), or climate variability.  The model also simulates changes in the important processes of assessment, decision-making and compliance.  With the Atlantis approach, stakeholders are empowered to explore the uncertainty of policy implementation when considering different management scenarios.  Use of CAM predictions will differ from the use of current, highly-developed single species model estimates that managers are accustomed to.  Ecosystem models necessarily incorporate data from a variety of temporal and spatial scales and of varying magnitudes; uncertainties from all of these data sources are carried over into ecosystem models.  However, CAM offers managers important new insights to environmental and societal tradeoffs that cannot be seen with simpler approaches.