New Report Finds California Ocean Biodiversity at Risk from Set Gillnet Fishery

Oceana and TIRN Urge Action to Protect Marine Mammals, Sharks, Skates, Rays, and Other Fish

MONTEREY, Calif., April 17, 2023 (GLOBE NEWSWIRE) -- Today, Oceana and Turtle Island Restoration Network (TIRN) released a report finding that the set gillnet fishery targeting California halibut and white seabass off Southern California is threatening the heath and diversity of the ocean ecosystem. This fishery throws overboard 64 percent of the animals caught, which is among the highest “bycatch” rates of any fishery in the country. These nearly invisible nets can be as long as the Golden Gate Bridge, and they indiscriminately catch more than 125 different species of ocean animals, including marine mammals, seabirds, sharks, rays, skates, and other fish that migrate, feed, and reproduce in the dynamic ocean waters off Southern California. More than half of the animals thrown overboard are already dead or dying when they hit the water — raising significant concerns over the fishery’s impact on California’s marine biodiversity. 

“The set gillnet fishery targeting California halibut and white seabass is clearly a risk to the health and resilience of California’s oceans,” said Caitlynn Birch, Pacific marine scientist with Oceana. “These nets injure and kill a myriad of ocean animals, including rare and vulnerable species. Despite a history of wildlife impacts and action by California voters, the fishery remains largely unmonitored as these nets continue to hurt wildlife off Southern California.”

“We are asking the state of California to walk the talk regarding being a global leader in the biodiversity crisis,” said Scott Webb, advocacy and policy director with Turtle Island Restoration Network. “As climate change continues to create a harsher environment for many of these vulnerable marine species, specifically sharks and whales, stronger protections are needed.”

Oceana and TIRN conducted an analysis which finds that:

  • 75 percent of sharks, skates, and rays that are caught are tossed overboard. These species are extremely important in marine ecosystems and vulnerable to overfishing.
  • Set gillnets are the primary threat to juvenile great white sharks in their nursery grounds off California. White sharks play an important ecosystem role, and their population is still at low numbers.
  • Gray whales and federally threatened and endangered populations of humpback whales are susceptible to entanglement in set gillnets.
  • More California sea lions are killed annually by set gillnets than all other observed West Coast fisheries combined.
  • Set gillnets throw back as waste dead commercial and recreational fish species — such as damaged and undersized California halibut, rock crab, sand bass, and lingcod — which can harm struggling populations and impact other recreational and commercial fisheries.

Management tools are available to reduce bycatch in California’s set gillnet fishery, and a more selective hook and line fishing method is already well-established. The California Department of Fish and Wildlife prioritized the set gillnet fishery as the first state-managed fishery that requires action to address its risk to the ecosystem. Oceana and TIRN, along with other conservation groups, marine mammal rescue centers, recreational fishing organizations, and businesses are calling on the California Fish and Game Commission — the managing authority — to reduce the needless waste set gillnets inflict on California’s ocean life in accordance with state law.

California set gillnets were originally banned in Northern California waters back in 1915. After southern Californian sport fishermen noticed major declines in fish populations in the 1980s, fishermen, environmental organizations, and elected officials worked together to address wildlife impacts caused by set gillnets. In a major victory for anglers and the marine ecosystem, California voters passed Proposition 132 in 1990, which prohibited the use of set gillnets within state waters off Southern California (0-3 nautical miles). In the late 1990s, scientists discovered set gillnets were also killing an alarming number of federally protected marine mammals and seabirds. In response, the California Fish and Game Commission banned the use of these nets off the Central California Coast in 2002. Due to the complexities of these various actions, most Californians are unaware that while set gillnets are banned in state waters off the Southern California mainland (0-3 nautical miles), they are still being used in federal waters, offshore banks, and in certain areas around Southern California’s Channel Islands, causing immense damage to wildlife.

Oceana is the largest international advocacy organization dedicated solely to ocean conservation. Oceana is rebuilding abundant and biodiverse oceans by winning science-based policies in countries that control one-quarter of the world’s wild fish catch. With more than 275 victories that stop overfishing, habitat destruction, oil and plastic pollution, and the killing of threatened species like turtles, whales, and sharks, Oceana’s campaigns are delivering results. A restored ocean means that 1 billion people can enjoy a healthy seafood meal every day, forever. Together, we can save the oceans and help feed the world. Visit to learn more.

Turtle Island Restoration Network (TIRN) is a global ocean conservation nonprofit based in Olema, California, whose mission is to inspire and mobilize people around the world to protect marine biodiversity and the oceans that sustain all life on Earth.

Contacts:Ashley Blacow-Draeger, Oceana,, 831-224-7484
 Scott Webb, TIRN,, 707-921-8211