Coastal connectivity in the Gulf of Maine in spring and summer of 2004–2009

Coastal ocean connectivity associated with the Gulf of Maine (GOM) surface flows in spring and summer seasons of 2004–2009 is studied using surface numerical particle tracking based on realistic regional ocean circulation hindcast solutions. Seven initial particle release sites are selected in key gulf regions often affected by harmful algal (Alexandrium fundyense) blooms, including Massachusetts Bay, the western GOM coastal area, the eastern GOM coastal area, the Bay of Fundy, Wilkinson Basin, the Jordan Basin, and a region seaward of Penobscot Bay. Surface particles are released every 5 days between February 1st and August 1st in each year, and the variability in their trajectories on interannual time scales is quantified by Lagrangian probability density function calculations. Coastal connectivity is further quantified using a connectivity matrix, identifying source and destination functions. Our results suggest that the interannual variability in coastal connectivity has strong impact on the spatial distribution of A. fundyense blooms in each year.