Shallow Rock and Kelp Forest Ecosystems, California South Coast MPA Baseline Study, 2011 to 2012

The SCSR is characterized by strong environmental gradients, a major defining feature of the SCSR compared to the other California MLPA Study Regions that have relatively more spatially consistent physical environments. These differences are reflected biologically in a high degree of kelp forest community structure across the region. We identified 17 geographically cohesive community clusters, each with distinct fish, invertebrate, and algal assemblages (Figure ES.1).

Although kelp forest communities in the SCSR are highly variable, the structure can be related to the sea surface temperature patterns caused by the confluence of the California Current, the Southern California Counter Current and localized upwelling. Benthic habitat structure also varies within the region; the geology and structure of island reefs are functionally different from mainland reefs. Mainland reefs generally are less steep, can be found significantly offshore of the coastline, and have a greater influence of sedimentation moving through the system.

With few exceptions, island reefs are generally abrupt, high relief structures, tightly fit to the coastline with less influence of the nearby soft bottom habitat. Ideally, long-term monitoring of MPAs should be distributed across the distinct areas as each is likely to respond differently.