Elkhorn Slough

Elkhorn Slough is an exceptional ecosystem on the central California coast providing a key linkage between land and sea. The slough harbors California’s largest tract of tidal salt marsh outside San Francisco Bay. Elkhorn Slough tidal habitats encompass extraordinary biological diversity, providing critical habitat for over 135 aquatic bird, 550 marine invertebrate, and 102 fish species.

Estuaries like Elkhorn Slough are, however, among the most threatened ecosystems in California, facing rates of habitat loss between 75 and 90 percent. As a result, a disproportionate number of rare, threatened, and endangered species reside in these areas. In the Elkhorn Slough watershed, two dozen species are included in these categories. Recognizing the value of these resources to the country, the National Oceanic and Atmospheric Administration designated areas of Elkhorn Slough as part of the Monterey Bay National Marine Sanctuary and as a National Estuarine Research Reserve.

The California Department of Fish and Game has also designated parts of Elkhorn Slough as a State Ecological Reserve and as a Wildlife Management Area, as well as designating three marine protected areas: the Elkhorn Slough State Marine Reserve and Conservation Area and the Moro Cojo State Marine Reserve. The National Audubon Society includes the slough in its Globally Important Bird Areas and the Western Hemisphere Shorebird Reserve Network designated it a Site of Regional Importance. The Nature Conservancy and Elkhorn Slough Foundation have invested in protecting over 3,500 acres of this watershed. These multiple designations and strategic land acquisitions reinforce the importance of this place as a key conservation asset.

One of the remarkable features of Elkhorn Slough is the diversity of human uses represented in a small watershed. The slough hosts the largest electric power generating plant in California. Additionally, the Moss Landing Harbor, at the entrance to the slough, is one of the most active fishing ports in the State. Elkhorn Slough is flanked by major transportation corridors including three state highways and the main north-south coastal rail line. One quarter of the land in the Elkhorn watershed is in agriculture, with farms in this area producing a significant proportion of the State’s strawberry crop. Residential housing is an increasing factor while recreational activities, including boating, kayaking, and birding, have increased dramatically over the past decade.

The Elkhorn Slough National Estuarine Research Reserve and Elkhorn Slough Foundation, together with numerous partners, are working to conserve and restore the slough and its watershed. Conservation activities include land acquisition and management, weed abatement, and wetland restoration. The research reserve also coordinates an extensive monitoring and research program. For more information see www.elkhornslough.org.