Spatial Dynamics Among Fishery Ecosystems in the Northwest Atlantic Coastal Shelf (NWACS) Large Marine Ecosystem

The northwest Atlantic coastal shelf large marine ecosystem (NWACS) is a complex mosaic of component ecosystems that are connected functionally by the movement of species among them.  Some species, such as striped bass, make movements that span the entire domain of the NWACS ecosystem; other species such as blue crab may only move between neighboring ecosystems.  Moreover, all species, no matter their level of vagility, are exposed to similar external environmental forcing.  However, the degree to which variation in vagility and environmental forcing couples the component ecosystems within the northwest Atlantic large marine ecosystem is unknown.  Here we analyze fishery-independent and fishery dependent data from 4 estuarine ecosystems and four nearshore coastal ecosystems within the NWACS ecosystem to assess similarities in the dynamical response of individual species and functional groups.  Dynamic factor analysis was used to analyze 30-40 year time series to assess whether and which species exhibited similar dynamics and to quantify the role of external environmental drivers in explaining these dynamics.  Results indicated that broad scale climatic indices such as the NAO were important in determining dynamics.  Moreover, results also demonstrated clear patterns of negative and positive covariation between estuarine and marine ecosystems and among species.