Marine Subtidal Rock and Boulders: Moderate to High Energy, Shallow (<15 m)

Subtidal bedrock and boulders have very similar assemblages, except on boulders small enough to roll in high currents. These habitats, like the rocky intertidal, are productive and diverse. Communities are often patchy, containing areas with herbivorous urchins and few kelps, or no urchins and many kelps. Kelp beds create a semi-protected habitat used as resting areas by gulls, heron, waterfowl, and cormorants, and as feeding sites by surf scoters and white-winged scoters, loons, grebes, goldeneyes, buffleheads, and harbor seals.  In their currently limited range along the outer coast, sea otters feed primarily in this habitat.

Diagnostic Species

The kelps Macrocystis integrifolia (outer coast), Nereocystis luetkeana, and Agarum spp.; the urchin Strongylocentrotus franciscanus, the anemones Metridium sp. and Epiactis lizbethi, encrusting corallines and fleshy red crusts, and rock greenling.

Common Associates

The brown algae Pterygophora californica, Pleurophycus gardneri, Desmarestia spp., and Laminaria spp., a wide variety of red algae, especially Gigartina corymbifera, Laurencia spectabilis, Iridaea splendens, Constantinea simplex, Plocamium cartilagineum, and Opuntiella californica.  Invertebrates include the urchins S. droebachiensis and S. purpuratus, the sea cucumbers Parastichopus californicus and Cucumaria spp.; the abalone Haliotis kamtschatkana, the snails Fusitriton oregonensis, Ceratostoma foliatum, Acmaea mitra, Lacuna spp., Margarites spp., Lirularia spp., and Calliostoma spp., Octopus dofleini, the chitons Tonicella spp. and Cryptochiton stelleri, the rock scallop Hinnites giganteus, kelp crabs (Pugettia spp.) and red rock crabs (Cancer productus), the seastars Pycnopodia helianthoides, Orthasterias koehleri, Henricia leviuscula, and Leptasterias hexactis, the anemone Urticina piscivora, the tunicate Styela montereyensis, and the orange finger sponge Neoesperiopsis digitata.

Fish found predominantly in these habitats include red Irish lord, longfin and scalyhead sculpins, and black, copper, Puget Sound, yellowtail, and quillback rockfish, kelp and painted greenling, lingcod, blackeye goby, cabezon, gunnels, and striped sea perch. The rockfish, hexagrammids, and seaperches are particularly associated with macrophytes.  Herring spawn on Nereocystis and Laminaria.

Sites Surveyed

Barnes and Allan Island, Tongue Point (Juan de Fuca), Neah Bay, and various sites in the San Juan Islands, including Point George, Edward’s Reef and Turn Island.


Shelford et al., 1935; Neushul, 1965 and 1967; Vadas, 1968; G.F. Smith, 1979; Irvine, 1973; Nyblade, 1979b; Moulton, 1977; Simenstad et al., 1988; Long, 1983; R. Kvitek, R. Shimek, R. Anderson, P. Gabrielson, and D. Duggins unpubl. data.