Center for Biological Diversity

For Immediate Release, April 20, 2023


Catherine Kilduff, (530) 304-7258,

Legal Agreement Spurs Analysis of California Gillnets’ Threat to Humpback Whales

Massive Fishing Nets Trap, Harm Marine Mammals, Sharks, Rays

SAN FRANCISCO— The National Marine Fisheries Service agreed today to complete a new assessment of the threat of drift gillnets in California to endangered humpback whales. In the 2020-2021 and 2021-2022 fishing seasons an estimated 12 Pacific humpbacks were caught in the California drift gillnet fishery, according to federal reports.

The fishery uses mile-long hanging nets, left in the ocean overnight, to catch large fish like Pacific bluefin tuna, swordfish and thresher sharks.

“Humpback whales just won a key victory against destructive gillnets,” said Catherine Kilduff, an attorney at the Center for Biological Diversity. “These amazing animals face so many threats off California, and absurdly huge nets are a hazard they really shouldn’t have to dodge. This agreement will help ensure whales are protected while the drift gillnet fishery winds down operations over the next five years.”

The Center sued the agency in 2022 over the fishery’s excessive harm to endangered humpback whales, which violates the Endangered Species Act. In addition, the Service’s existing 2013 review of endangered species failed to protect the humpback populations that were listed under the Endangered Species Act in 2016.

In the new biological opinion the Service will consider humpback whales entangled in Southern California recently and will ensure the fishery is not jeopardizing the continued existence of the species. The agency will also consider implementing measures to minimize the fishery’s harms to humpback whales.

Fishing gear entanglements are a leading threat to migratory endangered humpbacks along the West Coast. In April 2021, 48,521 square nautical miles were designated as critical habitat for the species.

West Coast humpback whale entanglement reports increased sharply from 2014 to 2017, reaching a record high of 53 entanglements in 2016. Since then, whale entanglements have remained elevated.

During the 2020-2021 and 2021-2022 fishing seasons, the Service observed fewer than 20% of the active gillnets, which means that because two humpbacks were seen tangled in nets, an estimated 11.7 were caught. Entanglements can lead to death, injury and lower calving rates in whales.

The most imperiled humpback population — which winters in Central America — has about 1,500 individuals and feeds almost exclusively off California and Oregon. The threatened Mexico population has about 2,900 individuals.

Bipartisan federal legislation that gradually ends drift gillnet use off the West Coast by 2027 was signed into law in 2022. A similar law was vetoed by President Trump in 2020.

State legislative efforts to phase out the fishery include California Senate Bill 1017, which was signed into law on Sept. 27, 2018, and directed the California Department of Fish and Wildlife to establish a voluntary program to incentivize drift gillnet permittees to transition out of the fishery.

humpback whale and calf
Humpback whale photo by Ed Lyman/NOAA permit # 774-1714. Image is available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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