Exploring California’s Marine Protected Areas: Blue Cavern Onshore State Marine Conservation Area and Blue Cavern Offshore State Marine Conservation Area

Just twenty miles off the coast of Los Angeles, Santa Catalina Island is home to about 4,000 people and nine marine protected areas (MPAs), including Blue Cavern Onshore State Marine Conservation Area (SMCA) and Blue Cavern Offshore SMCA.

Map of the west end of Santa Catalina Island. Four MPAs and one ASBS are located here.
map by CDFW Marine Region GIS Lab
(click to enlarge)

Protected from strong winds on the leeward side of Santa Catalina Island, Blue Cavern Onshore SMCA covers about 2½ nautical miles of ocean habitat, providing protection for rocky shores, surf grass beds, sandy seafloor, and sea caves. “There are a wide range of underwater environments here due to the steep topography of the island,” explained Ian Taniguchi, a California Department of Fish and Wildlife invertebrate specialist with years of experience diving in the area.

This “no-take” SMCA prohibits most common forms of “take” such as fishing or shell collecting; however, activities such as swimming, sightseeing, and diving are permitted as long as take restrictions are followed. With an approved scientific collecting permit on file, Blue Cavern Onshore SMCA also welcomes research, monitoring, and education efforts within its boundaries.

“The area around Blue Cavern Point and Big Fisherman Cove has been a no-take protected area for longer than its current MPA designation,” said Taniguchi, referring to the historical Catalina Marine Science Center Marine Life Refuge, which predated Blue Cavern Onshore SMCA by 30 years. “Due to the long period of protection, there is an outstanding variety and abundance of large fish and invertebrate species here, as well as rare species such as the Scythe Butterflyfish, Rainbow Scorpionfish, and Guadalupe Cardinalfish.

boat wake
Santa Catalina Island’s west end
CDFW photo by L. Gatlin

The state recognized the area as worthy of protection in the mid-1970s, prior to the establishment of any MPAs here, when it created four Areas of Special Biological Significance off Santa Catalina Island. The largest of these, known as the Northwest Santa Catalina Island Area of Special Biological Significance, now overlaps a small portion of the two state MPAs and prohibits most waste discharge from vessels and other sources in its waters. This additional protection for local species helps to safeguard the area from pollution, and preserve the water quality of the area’s biologically unique habitats.

Blue Cavern Onshore SMCA shares a deepwater boundary with its neighbor, Blue Cavern Offshore SMCA. With waters exceeding 2,500 ft. deep, Blue Cavern Offshore SMCA provides protection for bottom-dwelling species such as sea cucumbers, Lingcod, and some species of rockfish, while permitting commercial and recreational fishing for species such as Yellowtail and Pacific Bonito that live in the upper water column.

Blue Cavern Offshore SMCA also permits recreational spearfishing for White Seabass and dip-netting for market squid using a hand-held dip net. If you plan to fish in Blue Cavern Offshore SMCA, be sure to bring your recreational fishing license with you, or stop in the city of Avalon to purchase your fishing license beforehand (fishing licenses are not sold in the nearby village of Two Harbors).

Big Fisherman's Cove
Overlooking Big Fisherman’s Cove
CDFW photo by L. Gatlin

The University of Southern California (USC) Wrigley Marine Science Center, located on the shore of Blue Cavern Onshore SMCA at Big Fisherman’s Cove, is a state-of-the-art laboratory and teaching facility for ocean and land-based investigations. Research conducted on the island, including the USC Wrigley Institute’s Future of Food from the Sea program, has improved our fundamental knowledge of climate change science. Scientists there also conduct research on the ocean’s nitrogen cycle, ocean acidification, and more.

The marine science center plays hosts to a wide range of investigators, from veteran marine biologists searching for answers to the ocean’s most intriguing questions, to high school youngsters primed for their first exploration of underwater life. To this end, the center hosts a summer marine lab experience for high school students for one week every summer. Young ocean enthusiasts and biologists-in-the-making are given the opportunity work with researchers, conduct their own experiments, and build remotely operated vehicles that can dive into the local MPAs.

Visitors are welcome at the marine science center and both of the MPAs, which are accessible by boat (note that there is an anchoring restriction in one section of Blue Cavern Onshore SMCA). Diving, fishing in Blue Cavern Offshore SMCA, and sightseeing from a kayak or other vessel in the waters around Blue Cavern Point are popular activities. This long-protected jewel of blue ocean water, just a few hours from the crowded streets of Los Angeles, provides a breathtaking example of the rewards of ocean preservation inherent in California’s MPA Network.

Learn more about the MPAs near you by heading to our MPA Outreach Materials page or send us an email with your questions at AskMarine@wildlife.ca.gov!

Blue Cavern Onshore State Marine Conservation Area and Blue Cavern Offshore State Marine Conservation Area are two of the 124 MPAs in California’s statewide MPA Network. Please visit CDFW’s MPA website for more information, and sign up to receive updates about the MPA Management Program.

logopost by Stephanie Hubbard, CDFW Scientific Aid


Learn more about MPAs by diving into the
Exploring California’s Marine Protected Areas series! 

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