A Deeper Dive: Protecting Deep-Sea Corals in the Channel Islands

Visitors to the Channel Islands National Marine Sanctuary at Inspiration Point. Photo: Claire Fackler / NOAA

By Matt Coomer, Communications Coordinator at Marine Conservation Institute

Every year, the Channel Islands National Marine Sanctuary attracts hundreds of thousands of visitors to its beautiful rocky islands, historic sites, and abundant ocean wildlife. The Sanctuary is 25 miles off the coast of southern California, surrounding five of the Channel Islands. Because these islands are positioned where warm southern and nutrient-filled northern waters meet, they support many species drawn to their transitional richness. From dense kelp forests hosting diverse fish schools to open waters with migrating whales, there’s no shortage of life at the surface. Did you know, however, that far below the seabirds and sea turtles, that the Channel Islands National Marine Sanctuary (CINMS) hosts deep-sea coral reefs? And, more importantly, did you know that these fragile living treasures need our help?

Deep-sea corals, such as this bubblegum coral in the Channel Islands, are critical for fish populations. Photo: MARE

Over 90% of the CINMS is found more than 100 ft. below the ocean surface. Despite these depths having low oxygen and little sunlight, many ocean creatures have adapted to thrive in the harsh conditions. The ecological linchpins of the deep waters are corals and sponges: through building their skeletal structures, they create habitat for other invertebrates and many fish species. These animals depend on corals for safety from currents and predators, and use them as nurseries to protect their young. Because cold-water corals and sponges are often long-lived, one sponge was estimated to be over 11,000 years old, they have been called the “old-growth forests” of the seafloor. These ecosystems are, sadly, being lost around the world to human impacts like bottom trawl fishing and fossil fuel extraction. In light of these threats, the Pacific Fishery Management Council will ban some bottom-trawling around the Channel Islands, creating one of the West Coast’s largest fish habitat conservation areas. We applaud this progress, and hope to further conservation in these waters: Marine Conservation Institute went on an expedition with Marine Applied Research and Exploration (MARE) to help discover new deep-sea coral ecosystems in the area and advocate for their protection.

The MARE ROV (remotely operated vehicle) on the R/V Shearwater off the Channel Islands. Photo: MARE

Last May, we boarded the NOAA ship R/V Shearwater out of Santa Barbara to explore the Channel Islands on an eight-day expedition. Because seafloor coral and sponge communities are rare, our team prepared habitat suitability models (Figure 1) with environmental data to predict where we may find these ecosystems. The MARE team then used an ROV to explore over 2,000 ft. down and gather new data and high definition media. We have released new photos from the cruise on Twitter (through @savingoceans and @MAREgroup) and will share more as we analyze our results. We continue ramping up our work with the California Seamounts Coalition to protect other deep-sea ecosystems as well.

Figure 1: A habitat suitability model for soft corals within the CINMS. Warmer colors indicate more suitable habitat.

Though California’s state waters are well protected, the federal waters off its coast, from 3 to 200 nautical miles out, lack protection. This area contains seamounts and other deep-sea habitats with corals that support marine biodiversity and important ecosystem services, including nurseries for commercially valuable fishes. The California Seamounts Coalition is a group of dedicated environmental organizations, including Surfrider FoundationWildCoast, and Mission Blue, that support research and outreach for California’s deep-sea ecosystems. Our goal is to achieve formal protection for these habitats in the federal waters off California, and we invite you to learn more about our work and how you can help!

Bamboo coral on the Davidson Seamount with basket stars. This coral colony is estimated to be over 200 years old. Photo: NOAA/MBARI 2002

All life in our oceans is connected, and the Channel Islands National Marine Sanctuary’s famous richness descends well-below the whales we watch topside. The next time you think of corals, we hope you’ll dive deeper than the bright tropical reefs grabbing headlines. To keep the ocean healthy, we must also save the ancient corals and sponges of the seafloor. Together, we can protect these deep-sea wonders and keep our blue planet thriving for future generations. 


Marine Conservation Institute is a team of experienced marine scientists and policy advocates dedicated to saving ocean life. The organization’s goal is to create an urgently-needed worldwide system of strongly protected areas—the Global Ocean Refuge System—to protect marine biodiversity. Marine Conservation Institute also maintains the most accurate marine protected area database, the Atlas of Marine Protection.