The 2018 Marine Protected Area Monitoring Action Plan identified three bioregions for long-term marine protected area (MPA) monitoring: the north coast (California/ Oregon border to San Francisco Bay, including the Farallon Islands), the central coast (San Francisco Bay to Point Conception), and the south coast (Point Conception to the U.S./Mexico border, including the Channel Islands). These regions are distinct from the original five Marine Life Protection Act planning regions in which baseline monitoring occurred; the establishment of the five MLPA planning regions was intended to facilitate an MPA design process capable of accommodating the distinctive social and geopolitical attributes along the California coast. The three bioregions in the Action Plan were designated based on biological, ecological, and habitat data gleaned from baseline monitoring.

The shoreline provided in this feature is a general approximation of the mean high tide line at the time of MPA implementation between 2007 and 2012. However, it is important to note that it is not based on any elevation (tidal) data and was hand drawn based on best available aerial imagery at the time. Due to the dynamic nature of coastal environments, these boundaries may not accurately reflect the current condition or exact demarcations of the coastline. The offshore boundary is based on the National Oceanic and Atmospheric Administration (NOAA) three nautical mile maritime limit published on charts at that time.