140,000 Square Miles Of Seafloor Off US West Coast To Become Protected Habitat For Deep-Sea Corals And Sponges


Madison Dapcevich


Madison Dapcevich

Freelance Writer and Fact-Checker

Madison is a freelance science reporter and full-time fact-checker based in the wild Rocky Mountains of western Montana.

Freelance Writer and Fact-Checker


Deep-sea octopus and squat lobster seen by the Oceana expedition earlier this year off the coast of southern California. Oceana

More than 362,000 square kilometers (140,000 square miles) of seafloor habitat off the US West Coast is now protected under federal regulations published Monday. The new rules will protect the crucial coral, sponge, and rocky reef habitat from potentially destructive bottom trawling, according to a statement released by Oceana. 

The move follows a unanimous vote made by the Pacific Fishery Management Council in April to protect the region by doubling the spatial extent of seafloor protections in the Pacific waters off the western part of the continent. Once the measure goes into effect in January 2020, bottom trawling will be limited in 90 percent of the seafloor area in western waters.


Bottom trawling is a commercial fishing strategy that uses weights to drag large nets across the ocean floor to target a number of species, including fishes and crabs, according to NOAA. A number of protections put in place by fishers have limited the level of damage associated with bottom trawling, but bycatch and marine mammal entanglement remain a serious concern. Furthermore, towing a net across the ocean bottom has the potential to wipe out centuries-old coral and sponge species in deep-sea habitats previously unexplored by humans.

"There is broad scientific consensus that bottom trawling reduces the productivity, complexity, and biodiversity of seafloor habitats, and that these impacts are most severe and long-term in sensitive habitats like deep-sea corals, sponges, and rocky reefs," Oceana California campaign director and senior scientist Geoff Shester told IFLScience. "Some deep-sea corals live to be thousands of years old, so if they are crushed or removed by trawling, they may not recover for centuries." Shester has been involved in a number of Oceana-conducted seafloor expeditions whose collective work has documented over 30 species of commercial fish co-occurring with deep-sea corals and sponges, providing evidence of the importance of these habitats in maintaining critical fisheries. 

Bottom trawling is a commercial fishing strategy that uses weights to drag large nets across the ocean floor to target a number of species, including deep-sea fishes and crabs. NOAA.  

Shester notes that 98 percent of biodiversity in the ocean lives on the ocean floor and that deep-sea habitats are relatively protected from natural disturbances, which allows long-living species to grow. Because these delicate species are not adapted to disturbances, they are extremely fragile and provide vital habitat for other species who use the grounds to hide, feed, rest, and breed. Furthermore, Shester said that much of the seafloor has yet to be discovered so, without new protections, fishing may "destroy underwater treasures before humans even discover them." 

The new protections on the continental shelf and slope are part of Essential Fish Habitat. Oceana

The regulations protect key areas off the coasts of the states of Washington, Oregon, and California and protect habitats at depths of 3,500 meters (11,500 feet) and beyond from commercial bottom-contact fishing gear. They also reopen some historic fishing grounds that have recovered in recent years following the prohibition of bottom trawling. Combined, the final regulations note that these two changes “increase protections for groundfish essential fish habitat and provide additional flexibility to participants fishing with bottom trawl gear in the groundfish trawl rationalization program.”


Shester says that ultimately, these regulations were enacted because both fishing and conservation communities came together to ensure the vitality of important fisheries and ocean ecosystems. 

"Not only is this a success because of the new expansive protections for amazing areas off our coast, but because the new management regime is supported by the fishing community, making the protections much more long-lasting," he said.

"The new regulations are a gift to future generations of ocean lovers, undersea explorers, and seafood consumers."


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  • us west coast,

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