Carmel Submarine Canyon

Carmel Submarine Canyon, with its nearly vertical walls and flat floor with a steep gradient, is the closest to shore and the most accessible of any known submarine canyon. The head truncates in late Pleistocene and marine sediments.

The canyon has several branches, one directly off the Carmel River Valley , and the deepest and closest to shore, within a few tens of meters, off San Jose Creek; indeed, it appears to be the seaward extension of the creek, with the mouth filled by alluvium, for the submarine canyon is cut into granite, as is the creek's canyon. The canyon trends generally northwest to its junction with Monterey Canyon at a depth of 2,040 meters (6,700 feet) approximately 24 kilometers (15 miles) offshore.

There is evidence of faulting on the south side of the canyon, and a sand bottom and sand falls have been observed at 60 meters (200 feet) depth; rock types overlying the granitic base include Santa Lucia granodiorite and Carmelo conglomerate. Tributaries into the canyon form unique hanging valleys the action of turbidity currents is particularly noteworthy. Surrounding the canyon rim, 20 meters (60 feet) below the surface, is a submarine terrace, evidence of an earlier shoreline.

Among the many varieties of algae in the area, the giant kelp, Macrocystis pyrifera, is the most conspicuous inshore (see Carmel Bay Underwater Park), though other species are common, including Pterygophora californica, Nereocystis luetkeana, Laminaria spp., Calliarthron sp., Dictyoneurum sp., Egregia spp., Cystoseira sp., and Costaria sp. In depths of less than 20 meters (70 feet) red algae, particularly the encrusting Lithothamnium sp., is especially noticeable.

Some 290 species of marine invertebrates, including 122 molluscs, have been identified in the area. Among the invertebrates the tube worm, Diopatra ornata, the gorgonians Psammogorgie arbuscula and Euplexaura marki, the latter particularly noticeable in the 30-meter (100-foot) zone, the molluscs, Hemitoma bella, Haliotis kamtschatkana, Acmaea funiculata, the polychaete worm, Phyllochaetopterus prolifica, as well as several starfish, are common. Several sponges, including Hymenamphiastra cyanocrypta and Tethyia aurantia californica, and the red anemone, Corynactis californica, are conspicuous, as is the cup coral, Balanophillia elegans. The rare hydrocoral Allopora californica occurs here.

Several hundred species of fish may be encountered in the area. Killer whales, Orcinus rectipinna, the California gray whale, Eschrichtius glaucus, and various other whales, dolphins, porpoises, seals and sea lions may be seen in the area.

Integrity: Pristine, save for the inshore heads where accessibility has led to over-collecting.

Use: Research, educational, observational.

Ref: Peckham, V. O. and J. H. McLean, 1961. Biological Explorations at the Head of Carmel Submarine Canyon, Abstracts Annual Report of American Malacological Union, 48 pp.
McLean, J. H. Sublittoral Ecology of Kelp Beds of the Open Coast Area near Carmel, Calif. Biol. Bull. No. 122, pp. 94-114.
Moritz, C. A. 1968. A Descriptive Survey of the Head of Carmel Submarine Canyon, Unpub. M.S. Thesis. Naval Postgraduate School, Monterey, Calif.

August 1976