Marine Intertidal Sand: Exposed and Partially Exposed

Pure marine sands without significant silt or organic content are found only in high and moderately-high energy areas such as on the outer coast and in the Straits of Juan de Fuca. They tend to be erosional beaches, are well-drained, and moderately sloped.  Due to their unstable nature, they have no permanent vegetation and are low-diversity habitats, although a few species may be abundant.  These areas are used extensively by loons, scoters, and grebes at high tide, and by gulls, sanderling and other sandpipers, and herons at low tide.

Diagnostic Species

Phoxocephalid amphipods and Eohaustorius spp., the polychaete Paraonella platybranchia, the mysid Archaeomysis grebnitzkii, and the olive shell Olivella biplicata and the razor clam Siliqua patula (patchy but locally abundant on the outer coast).  Diagnostic fish species are juvenile Pacific tomcod and English sole, Pacific staghorn sculpin, sand sole, and redtail surfperch.

Common Associates

The isopod Excirolana vancouverensis, the amphipods Proboscinotus loquax and Megalorchestia californiana, the polychaetes Euzonus mucronatus, Streptosyllis latipalpa, Abarenicola pacifica, Axiothella rubrocincta, Magelona sp, and Nephtys spp.; and nemertean worms. Seines reveal shrimp (Crangon spp.), soles, starry flounder, Pacific sand lance, Pacific tomcod, pile, surf, and shiner perch, various sculpins, crescent gunnels, sturgeon and tubenose poachers, and sometimes schools of Pacific herring and surf smelt.

Sites Surveyed

West Beach on Whidbey Island, North Beach (Quimper Peninsula), Kydaka Beach, Eagle Cove on San Juan Island, outer coast beaches.


Webber, 1980; Nyblade, 1979a,b; Cross et al., 1978; Dethier, 1988; Albright et al., 1980; Long, 1983; H. Wilson unpubl. data.