This data is a statewide compilation of California's Marine Life Protection Act (MLPA) Study Regions.

As part of a comprehensive effort to sustain marine habitats and fisheries, the Marine Life Protection Act (MLPA) of 1999 directed the State to redesign California’s system of marine protected areas (MPAs) to function as a network. To facilitate planning, the MLPA Initiative, a public-private partnership, was formed and the state was divided into five planning regions (four coastal and the San Francisco Bay), each with its own MPA planning process. All four coastal regions have now completed their individual planning processes, leading to the statewide implementation of California's MPA network along the coast. Options for a planning process in the fifth and final region, the San Francisco Bay, have been developed for consideration at a future date.

Twenty MPAs and six special closures were implemented in the north coast region, from the California/Oregon border to Alder Creek (near Point Arena), on December 19, 2012.

Twenty-five MPAs and six special closures were implemented in the north central coast region, from Alder Creek (near Point Arena) to Pigeon Point, on May 1, 2010.

Twenty-nine MPAs were implemented in the central coast region, from Pigeon Point to Point Conception, on September 21, 2007.

Fifty MPAs and two special closures were implemented in the south coast region, from Point Conception to the California-Mexico border, on January 1, 2012.

The shoreline provided in this feature is a general approximation of the mean high tide line at the time of implementation. 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.