Marine Intertidal Boulders

No specific surveys have been done in these habitats, which generally resemble bedrock shores of similar wave exposures.  A few species are more common in boulder fields than on bedrock shores, probably because the bases of boulders provide protection from sun and from predators: these include the red algae Plocamium cartilagineum and Prionitis spp., the limpet Tectura persona, the turban snail Tegula funebralis (outer coast only), the shore crab Hemigrapsus nudus and the red rock crab Cancer productus, the anemones Metridium senile, Urticina crassicornis, and Anthopleura xanthogrammica (outer coast); and several tunicates (especially Pyura haustor) and intertidal sponges (Halichondria panicea, Haliclona permollis, and Ophlitaspongia pennata). Characteristic species in the gravel commonly found at the base of boulders include the northern clingfish, porcelain crabs Petrolisthes spp., sipunculid worms, and the polychaete Thelepus spp.