These data represent nearshore zones and are a part of PMEP’s spatial data system. This layer was developed as part of a larger Nearshore Project in order to extend PMEP’s current data system into the nearshore. Previously, PMEP’s spatial data system consisted of PMEP’s full scope (i.e., coastal watersheds out to a 200 m depth in marine waters), and included four ecoregions and 444 estuaries across Washington, Oregon, and California. This layer subdivides the marine waters of PMEP’s scope into zones based on depth (-30 m, -100 m, and -200 m or the state boundary line, whichever is deepest) and 18 sub-regions integrated within four ecoregions. Definitions of the nearshore zones in this dataset are based on Marine Subsytems defined by the Coastal and Marine Ecological Classification Standard (CMECS) with slight modifications as recommended by regional experts. For full documentation of CMECS, see https://coast.noaa.gov/data/digitalcoast/pdf/cmecs.pdf.