This Area of Special Biological Significance (ASBS) includes the northern group of California’s Channel Island chain. Santa Cruz Island is the largest and most biologically diverse, including 12 species found nowhere else on earth. It is owned mostly by the Nature Conservancy; what remains is part of Channel Islands National Park. Santa Cruz Island has 77 miles of coastline, two mountain ranges and a valley caused by an earthquake fault. San Miguel and Santa Rosa Islands are also part of the national park. The islands are between 25 and 40 miles off the coast of Santa Barbara and Ventura Counties.

Major pollution threat is the dense urban development on the mainland and contamination from shipping lanes.

ASBS Area: 274,468 acres

County: Santa Barbara

Regional Board Area: Central Coast RWQCB

Year designated: 1974 (Resolution 74-28)

ASBS Index No.: 17