BCG approaches for improved management of estuaries

Estuaries and other complex aquatic systems are exposed to a variety of stressors that act at several scales, but are managed piecemeal - - often resulting in a “death by 1000 cuts” caused by cumulative impacts to these valued resources.  To address this, managers need tools that can provide context for meaningful interpretation, assessment, and goal-setting within a larger view of the estuary and watershed.  The intent of a Biological Condition Gradient (BCG) approach is to assist with assessment, goal-setting, and management of waterbodies.  A national workgroup is expanding the traditional BCG approach to create an integrative framework for managing estuaries at several scales.  We present the evolving details of this workgroup’s estuarine BCG-based science and management framework, illustrated with data from a National Estuary Program pilot system.  Our framework considers structure, function, condition, connectivity, and invasives in waterbodies at multiple scales, including the whole-waterbody scale (e.g., comprehensive water column measures, measures of the estuarine mosaic of living habitats) and the single-habitat scale (e.g., seagrass health measures, benthic faunal indices).  This holistic and integrated approach is intended to improve our understanding and management of the cumulative impacts of multiple stressors in complex waterbodies.