Steven Morgan, Ph.D.
Bodega Marine Laboratory
University of California, Davis
What's limiting larval recruitment along our coast?
Wednesday — September 12, 2012
Pacific Forum — 3:00 p.m.
Seminal research conducted off Monterey Bay proposed that larvae are highly vulnerable to offshore transport in upwelling regions along the eastern margins of continents, thereby limiting recruitment to infrequent wind-relaxation events and years of weak upwelling. In contrast, several recent studies conducted in the strong, persistent upwelling off Northern California have shown that a diverse array of crustacean larvae are neither advected offshore nor limited to recruiting during relaxation events. Reliable interspecific differences in larval behavior regulate the distances larvae disperse cross-shelf and likely alongshore, affecting population connectivity. Few larvae occur in fresher water originating from San Francisco Bay, and larval behaviors and distributions are altered upon the arrival of this water along the open coast north of the bay during relaxation events thereby limiting recruitment. Spatial and temporal variation in surfzone hydrodynamics also may play a substantial role in regulating recruitment to communities in upwelling regions.