Marine Subtidal Cobble: High Energy, Deep
Several sites, surveyed by dredging, consist of a “scoured” substratum consisting largely of cobbles. All these sites were in channels or passes with high currents that affect the substratum well below 15 m.
Diagnostic Species
The horse mussel Modiolus modiolus, the giant barnacle Balanus nubilus, the serpulid worm Serpula vermicularis.
Common Associates
The urchins Strongylocentrotus pallidus and S. droebachiensis, the rock scallop Hinnites giganteus, the fan worms Sabellaria cementarium and Schizobranchus insignis, hydroids, ophiuroids, occasionally the basket star Gorgonocephalus eucnemis, anemones, and clam Humilaria kennerlyi.
Sites Surveyed
Haro Strait, Deception Pass, sites in the San Juan Islands.
Sources
Wennekens, 1959; R. Shimek, R. Anderson unpubl. data.