Few sites of this habitat type have been surveyed for benthic organisms, although the fish fauna has been more thoroughly sampled (reviewed in Long 1983). Two sites in the Strait of Juan de Fuca exposed to strong wave action and swells were classified by the investigators as gravel.
Mysella tumida, Leptochelia savignyi, the polychaetes Tharyx multifilis and Mediomastus sp., ophiuroids, the isopod Gnorimosphaeroma oregonense, and the snail Amphissa columbiana. A wide variety of sculpins, perch, flatfish, and others use these and more mixed-substratum habitat types.
Morse Creek (near Port Angeles), Twin Rivers.