Editor’s note: This is the second in a three-part series by longtime ocean advocate Dan Haifley on the role that national marine sanctuaries play in our nation’s landscape.

Nearly all the water that covers 71% of our planet is contained within our ocean, arguably earth’s most prominent feature. Half the oxygen we breathe is produced by plant life there, including phytoplankton at the bottom of the food web. Life within it is vulnerable to climate change and other threats.

To help protect it, our nation’s marine sanctuary system manages portions of our Great Lakes and oceans for their cultural, ecological, research or historic value. It started with the Marine Sanctuaries Act approved by Congress in 1972, a plank in a raft of environmental laws proposed in response to the 1969 Santa Barbara oil spill. Today 17 sanctuaries and two marine national monuments cover 629,000 square miles. Six of those, covering about 20,000 square miles are off our West Coast: one in Washington state and five in California.

Channel Islands National Marine Sanctuary was designated in October 1980, to encompass 1,470 square miles Anacapa, Santa Cruz, Santa Rosa, San Miguel and Santa Barbara islands off Ventura and Santa Barbara counties. Warm water collides with cold here to produce a unique mix of wildlife; sea grass lives in shallow waters with dense kelp forests farther offshore, blue and humpback whales feed here and elephant seals, harbor seals, California sea lions and Northern fur seals use the islands as rookeries. The sanctuary contains habitats for endangered black abalone and white abalone. About 60 seabird species feed here, and a permanent rookery for threatened brown pelicans is here. The sanctuary team’s projects include seafloor mapping, deep sea corals and ocean sound, as well as citizen science, reducing whale fatalities from ship strikes and removing marine debris (channelislands.noaa.gov).

Chumash Heritage National Marine Sanctuary, named for Indigenous people who’ve navigated these waters for thousands of years, is the newest West Coast site, designated on Nov. 30, 2024. It covers 4,543 miles along 116 miles of San Luis Obispo and Santa Barbara county coastline, from Avila Beach to Point Conception. Its research, education and protection projects will be managed collaboratively with Indigenous governments and organizations. It has several submerged cultural sites, and its topography includes the 5,500-foot-tall Rodriguez Seamount whose summit is 650 feet below the surface, Arguello Canyon and part of the Santa Lucia Bank. The area contains a transition zone where cold and warm waters meet, and where underwater currents thrust cold nutrient rich waters to the surface, feeding an array of marine life. (sanctuaries.noaa.gov/chumash-heritage/ or chumashsanctuary.org).

Monterey Bay National Marine Sanctuary was designated in September 1992, and today covers 6,094 square miles hugging 276 miles of coastline from Cambria to Marin County, including the 7,500-foot-high Davidson Seamount whose summit is 4,000 feet below the surface, and the 2 ½ mile deep Monterey Bay Submarine Canyon. kelp forests, rocky shores, sandy beaches and estuaries host 36 species of marine mammals, more than 180 species of seabirds and shorebirds, at least 525 species of fishes, and invertebrates and algae. The USS Macon, a dirigible that went into the sea off of Big Sur, is preserved along with two crew members whose lives were tragically lost. The sanctuary’s team deals with derelict vessels that pose environmental threats, collaborative research on deep-sea corals and environmental DNA, volunteer water quality and education programs, including the Sanctuary Exploration Center near the Santa Cruz Wharf with 60,000 visitors per year (montereybay.noaa.gov).

West Coast sanctuaries collaborate together to train and deploy a team that responds to whales entangled in lost fishing gear, encourage cargo ships to slow down to avoid fatally striking whales and reduce emissions, catalog and preserve maritime heritage sits such as shipwrecks and Indigenous culture, and conduct research projects within the California Current that drives productivity along the length of the West Coast.

My next and last installment on West Coast national marine sanctuaries: Greater Farallones, Cordell Bank and Olympic Coast.

Dan Haifley was the first executive director of Save Our Shores, and O’Neill Sea Odyssey.