Eelgrass Data

Eelgrass is a flowering marine plant that provides many biological and ecosystem services including shelter for juvenile fishes, shoreline stabilization and water quality improvements. It grows in quiescent bays and harbors as well as open coast regions. However, its distribution may change over time as a result of variable growth conditions. While eelgrass maps may require frequent updating, historic data may identify areas of persistent growth and give an idea of maximum potential extent within a system. NMFS has been facilitating the collection of data on eelgrass distribution because it assists project managers in avoiding, minimizing or offsetting the impacts of coastal development projects, supports the design of research projects and promotes awareness to the public. These data are available for download as GIS shapefiles and include associated survey reports, where completed. Please send additional inquiries regarding these data to

System Year Shapefile (zip) Report (pdf)
Southern California
Agua Hedionda Lagoon 2013 Shapefile Report 3.5MB
Alamitos Bay 2013 Shapefile Report 3.5MB
Anaheim Bay 2013 Shapefile Report 3.5MB
Batiquitos Lagoon 2013 Shapefile Report 3.5MB
Huntington Harbor 2013 Shapefile Report 3.5MB
Lower Newport Bay 2004 Shapefile Report 6.1MB
Lower Newport Bay 2007 Shapefile Report 692kb
Lower Newport Bay 2010 Shapefile Report 10.2MB
Lower Newport Bay 2013 Shapefile Report 6.7MB
Mission Bay 2007 Shapefile Report 70MB
Mission Bay 2013 Shapefile Report 11MB
San Diego Bay 1993 Shapefile
San Diego Bay 1999 Shapefile
San Diego Bay 2004 Shapefile
San Diego Bay 2008 Shapefile Report 4.2MB
San Diego Bay 2011 Shapefile Report 4MB
San Diego Bay 2014 Shapefile Report 2.9MB
San Dieguito Lagoon 2013 Shapefile Report 3.5MB
Santa Cruz Island 2015 Shapefile Report 7.9MB
Santa Monica Bay 2015 Shapefile Report 7.9MB
Central California
Morro Bay 2007 Shapefile
Morro Bay 2009 Shapefile
Morro Bay 2013 Shapefile Report 6.9MB
Morro Bay Aggregate 2013 Shapefile Report 6.9MB
Northern California
Albion River (Mendocino) 2014 Shapefile
Big River (Mendocino) 2015 Shapefile
Drake's Estero 2005 Shapefile
Humboldt Bay/Eel River 2009 Shapefile Report 7.1MB
Tomales Bay 2015 Shapefile
San Francisco Bay 2004 Shapefile Report 29MB
San Francisco Bay 2009 Shapefile Report 45MB
San Francisco Bay 2014 Shapefile Report 79MB