Characterization of Ocean Acidification Impacts in the Southern California Bight with a Coupled Chemical-Biological Monitoring Program

Ocean acidification (OA) will affect the distribution, abundance and physiological fitness of marine life, and will shape ecosystem structure and function in the years to come. Recent monitoring of carbonate chemistry in the Southern California Bight (SCB) indicates that coastal waters routinely experience carbonate saturation states expected to impact calcifying organisms; however, measurements of in situ biological impacts are lacking. Coupled chemical and biological monitoring for OA has been identified as a fundamental attribute of effective OA monitoring programs. To meet this need, we are piloting a regional monitoring program for assessing biological impacts of OA in the SCB with the support and collaboration of local regulatory and regulated management agencies, nongovernmental organizations and academic researchers. While several candidate indicator species and biological metrics have been suggested, there is no consensus on appropriate biological metrics or endpoints. Thus, the goal of this program is to establish regionally important indicator species and sensitive biological metrics to assess OA impacts in SCB pelagic waters. Here we demonstrate preliminary results for candidate taxonomic groups and biological metrics along a north-south offshore transect along the continental shelf.