We systematically surveyed 94 of the 122 nearshore rocky reefs in the California south coast study region (SCSR). This synoptic baseline survey was conducted at 75 individual sites in 2011 and 88 sites in 2012. In addition, we incorporate two similar ‘historical’ data sets from 59 sites in 2004 and 79 sites in 2008. From 2011-2012, we surveyed all accessible nearshore rocky reefs found in the SCSR MPAs and determined the appropriateness of references areas for each. This baseline provides, for the first time, a taxonomically exhaustive biogeographic assessment of the nearshore subtidal reefs in the SCSR, improving significantly on our knowledge of the region and incorporating newly established and existing MPAs. Results confirm previously described patterns for subtidal fishes, reflect the physical oceanographic complexities of the Southern California Bight and add new knowledge to biogeographic patterns of algae and invertebrates. 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.

Reef Check California has surveyed rocky reefs and kelp forests in southern California since 2006 and has up to nine years of data from the MLPA South Coast Study Region (SCSR). The goal of this baseline monitoring project is to quantify key attributes of species, populations, communities and habitat variables that constitute representative kelp forest ecosystems within and outside of many of the MPAs in the South Coast Study Region. The sampling design, selected response variables (i.e. key species) and analytical approaches are intended to provide scientists, managers, stakeholders and policymakers with a baseline for future assessment of the effectiveness of the SCSR MPAs. Further, the outcomes from this study will also provide recommendations for long-term monitoring metrics and cost-effective survey protocols for the SCSR. Specific objectives are: 1. Provide a quantitative baseline characterization of the rocky reef and kelp forest ecosystem feature inside and outside of MPAs in the SCSR. 2. Provide pre-MPA implementation data and historical context to ongoing data collection by analyzing RCCA’s existing dataset in the context of the new MPAs. 3. Explore the baseline characterizations for potential indicators of the state of the kelp forest ecosystem (i.e. ecosystem indicators) and make recommendations for long-term monitoring. 4. Build capacity for cost-effective, long-term MPA monitoring through the continued involvement of community members in the monitoring of MPAs. 5. Expand existing public online data dissemination and illustration tool (NED) to inform managers, stakeholders, policymakers and the public about the status of the marine environment in the SCSR.

RCCA volunteer citizen scientists conducted 18 visual scuba transects at each monitoring site to survey densities and sizes of ecologically and economically important fish, invertebrate and algal species and to characterize the physical habitats. Transects were 30-meters long and 2-meters wide swaths above the rocky reef substrate. Divers counted and sized key species of fish (35 species), counted invertebrates (33 species) and algae (9 species), and estimated the percent cover of substrate types and vertical relief of the seafloor. Over the baseline monitoring of 2014-2015, RCCA conducted 18 surveys at eight monitoring sites in the NCSR. Three of these sites have been surveyed since 2007. The data from these surveys were analyzed at multiple scales to provide baseline characterization of the kelp forest ecosystems at the time of MPA implementation. We characterized the biological community at the RCCA monitoring sites by summarizing the physical and biological characteristics of each of the sites. These summaries will serve as a reference point in the future as long-term monitoring continues.

To characterize the fish communities associated with nearshore rocky reef habitat, we collaborated with commercial passenger fishing vessel (CPFV) captains and volunteer anglers to conduct hook-and-line surveys in four pairs of MPA and reference sites. Sampling was conducted with scientific crews of six: four anglers, a sampler who handled, measured, and tagged fish, and a data recorder. Each of the four anglers used a different combination of baited or un-baited lures that represented gear frequently used by recreational anglers to catch the target species. Sites were sampled by fishing for 45 minutes in each of four, 500 meter by 500 meter sampling cells, which were randomly selected from a set of cells that covered bottom areas containing at least 20 percent rocky reef habitat, by area. Captains were directed to drift within the cells over areas of rocky habitat for a maximum of 15 minutes per drift, so that at least three areas of habitat within each cell would be sampled. Captured fish were identified to species, measured to the nearest millimeter in fork length, tagged with an external t-bar anchor tag, and returned to the water, using a descending device if needed. Each site was sampled five times, three from June-October 2014, and twice from May-August 2015.