Programs & Events

Shoreline Stewardship Program Eelgrass Protection Program Workshops & Events Tribal Partnerships Anti-Litter Program

Shoreline Species & Habitats

Forage Fish Eelgrass Kelp Salmon Coastal Forests

Human Impacts

Shoreline Armoring Docks Clearing & Grading Stormwater Toxins in Our Water Voluntary Conservation Programs

Compared to nearby barren, shifting sands, the eelgrass meadow is full of life.  As in an old-growth forest, there are habitats in every niche.

Eelgrass beds grow in shallow bays and coves, tidal creeks, and estuaries.  They serve as a haven for crabs, scallops, numerous species of fish, and other wildlife, providing these creatures with habitat, nursery grounds, and food.  The long blades of grass are often covered with tiny marine plants and animals.  Species commonly associated with eelgrass meadows in San Juan County include Pacific herring, out-migrating juvenile salmon, Dungeness crab and Great Blue Herons.

The native eelgrass (Zostera marina) is considered a keystone species in the Pacific Northwest, providing critical habitat for hundreds of important marine species, including juvenile salmon, Pacific herring, black brant, river otters and Dungeness crab.  Each blade of eelgrass is a small food factory.  Diatoms, bacteria, and detritus (decaying plant and animal matter) gather on eelgrass leaves.  This detritus provides food for many invertebrates; isopods, amphipods, polychaete worms, brittle stars, and some clams. 

The large number of invertebrates makes eelgrass beds rich feeding areas for fish and marine birds.

Eelgrass also provides structural complexity to the nearshore, functioning as habitat, mitigating wave energy and trapping fine sediments.  Connectivity of eelgrass communities can play an important factor in habitat character, supporting salmon as they move through the nearshore.  In 2004, FRIENDS of the San Juans, in partnership with the University of Washington and the Washington Department of Natural Resources, completed comprehensive eelgrass mapping that documented 140 linear miles of eelgrass in San Juan County.  The eelgrass is distributed along bays, beaches and offshore banks; click here to see a map of San Juan Countys eelgrass habitat (outerline only).

Threats to eelgrass include: changes in light, temperature, nutrient and chemical conditions; sediment from erosion caused by logging and development, which limits light and coats marine vegetation; dredging that can directly destroy plants and add to water quality problems; docks and marinas that block the sunlight eelgrass plants require to grow; and polluted stormwater runoff from a range of upland practices such as clearing and grading and use of lawn and garden chemicals.