SAN FRANCISCO - An environmental group has sued the state of California for allegedly not doing enough to keep Dungeness crab fishery gear from killing protected whales.

The Center for Biological Diversity filed its lawsuit Tuesday in federal court in San Francisco, saying the California Department of Fish and Wildlife is liable for a surge in entanglements of endangered whales and sea turtles because it authorizes and manages operation of the fishery.

California should put in place more mandatory protection measures, such as blocking fishing operations from especially important waters for whales, restricting the amount of gear in whale hotspots and reducing the amount of rope running through the water, the centre said.

"These entanglements are heartbreaking, illegal and way too common," said Kristen Monsell, a senior attorney with the Center. "California officials can't let this minefield of crab traps continue to slaughter endangered whales and sea turtles."

Kirsten Macintyre, a spokeswoman for the California Department of Fish and Wildlife, said the centre has a longstanding policy not to comment on pending litigation.

The pots and lines used by crab fishing boats can get carried away by waves or by vessels that accidentally snag whales and turtles. The animals can drag fishing gear for hundreds of miles and often die from their entanglement injuries.

Entanglements of whales have broken records on the West Coast in each of the past three years. There were 71 reported whale entanglements last year, up from 62 in 2015 and 30 in 2014. Before that, whale entanglement reports averaged fewer than 10 per year, it added.

The California commercial Dungeness crab trap fishery entangles more endangered whales and sea turtles than any other U.S. West Coast fishery. Many of last year's entanglements were clustered around the biologically rich Monterey Bay, where migrating whales came to feed, according to the centre.

California fishermen and port officials working with the Nature Conservancy environmental group this year launched a program to recover lost or abandoned ropes, buoys and anchors of fishing gear from the ocean in an effort to reduce the number of entangled animals.

Noah Oppenheim, executive director of a group that represents West Coast commercial fishermen, said the lawsuit is disappointing and that fishermen and women take the health of the ocean "incredibly seriously."

"We do everything we can to avoid whales when we fish, and fishermen have risked life and limb to help whales escape in some of the rare instances in which they do become entangled," said Oppenheim, of the Pacific Coast Federation of Fishermen's Associations.

News from © The Associated Press, 2017