Santa Barbara Island
Map SatelliteSanta Barbara Island is the smallest of the Channel Islands and is classed with the southern group. It is located 61 kilometers (38 miles) from the mainland and 38 kilometers (24 miles) to the nearest island, Santa Catalina. (See Santa Catalina Island - Avalon Canyon, Ben Weston Beach, Bird and Indian Rocks, Black Jack Mountain Reserve, Black Point, Black Ridge, Bullrush Canyon, Catalina Harbor and Salina, Cherry Valley, Fisherman's Cove Area, Gallagher's Canyon, Ironwood Gully, Little Harbor / Cottonwood Creek, Mount Orizaba to Mount Banning, Parsons Landing, Renton Mine Area, and Swains Canyon)
Both flora and terrestrial fauna are depauperate. A total of 40 native species or subspecies have been collected on the island. Of these, only two, the rare Dudleya traskiae and Eriogonum giganteum var. compactum, are endemic to the island. Ten other species endemic to the Channel Islands are found here, Lotus argophyllus ssp. argenteus, Phacelia floribunda, Artemisia nesiotica, Eriophyllum nevinii, Malacothrix foliosa, Malacothrix squalida, Hemizonia clementina, and the rare species Astragalus traskiae, Eschscholzia ramosa and Lavatera assurgentiflora.
The vegetation is primarily exotic grassland and there are no trees on the island. The once extensive, and probably still the largest, stands of the giant coreopsis, Coreopsis gigantea, which reach 3 meters (10 feet) in height, have been severely reduced by the introduced species.
Only one terrestrial mammal, the deer mouse, Peromyscus maniculatus elusus, and the island night lizard Klauberina riversiana, are native to the island. There are several rare and endemic snails. Santa Barbara Island supports one of the of the principal rookeries of the California sea lion, Zalophus californianus. The northern elephant seal, Mirounga angustirostris also breeds here, as do a number of sea birds.
The marine biota is a rich mix of both northern and southern elements. Offshore are giant kelp, Macrocystis pyrifera, beds.
The island is composed primarily of a mid-Miocene vesicular massive basalt overlain by a basaltic agglomerate. A thin bed of shale separates the two volcanic elements. Portions of the island are covered by mid and upper Pleistocene marine terrace deposits and there are fossils present.
The island has an extremely precipitous shoreline, ranging from cliffs a few meters high to more than 150 meters (500 feet). There are rocky bays and a few sandy beaches as well as numerous caves, rock bridges and sea stacks.
Integrity: The introduced European rabbit, Oryctolagus cuniculus, and the once abundant sheep have severely disturbed the native flora. Aside from two lighthouses, there is no development.
Use: Research, educational, observational. The island has been a part of the Channel Islands National Monument since 1938.
Ref: Philbrick, R. N. 1972. The Plants of Santa Barbara Island, California. Madrono, Way 25.
March 1977
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman
