Elkhorn Slough

Overhead Photo
Great Egrit
Shore Birds
Oyster Restoration Reef
Eel Grass Bed

Elkhorn Slough

  • Country: 
    United States of America
  • Site number: 
  • Area: 
    724 ha
  • Designation date: 
  • Coordinates: 
    36°50'N 121°45'W
Materials presented on this website, particularly maps and territorial information, are as-is and as-available based on available data and do not imply the expression of any opinion whatsoever on the part of the Secretariat of the Ramsar Convention concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries.


The Site is a seasonal estuary comprised of intertidal marshes, mudflats and seasonal brackish pools. The Slough harbours eelgrass beds as well as oyster communities, which provide valuable fish nurseries, and the intertidal mudflats nourish migratory shorebirds. These distinctive estuarine communities are among the rarest and most threatened habitat type in California, which has lost approximately 91% of its wetlands in the last 100 years. This biologically rich estuary provides habitat for more than 340 species of birds, with more than 20,000 waterbirds, more than 500 species of invertebrates, and 100 species of fish, including the representative bat ray (Myliobatis californica) and leopard shark (Triakis semifasciata). It also provides key habitat for more than 100 individuals of southern sea otter (Enhydra lutris nereis) that feed, nest and nurse in the area. This wetland also provides diverse ecosystem services such as pollution control, climate regulation, food provision, and recreational, educational, and research opportunities, attracting thousands of birdwatchers every year. The Site has also been designated as a Globally Important Bird Area by the National Audubon Society and as a Western Hemisphere Shorebird Reserve Network of Regional Importance.

Administrative region: 
Monterey County, California

  • National legal designation: 
    • NMFS Essential Fish Habitat - N/A
    • NOAA National Estuarine Research Reserve - Elkhorn Slough National Estuarine Research Reserve
    • State Marine Conservation Area - N/A
    • State Marine Reserve - Elkhorn Slough State Marine Reserve
  • Last publication date: 


Ramsar Information Sheet (RIS)

Additional reports and documents