Federal fishery managers denied a proposal this week to immediately shut down Southern California’s most controversial fishery in the event that wide-mesh gill nets accidentally kill a handful of certain marine mammals or sea turtle species.

The swordfish and thresher shark fishery will remain open, even if it kills several whales or sea turtles, the NOAA’s National Marine Fisheries decided.

The decision not to institute so-called hard caps on the fishery comes after a public review period initiated last year was extended to discuss the law proposed by the state’s Pacific Fishery Management Council in 2014.

For the few dozen fishers who still catch swordfish and thresher sharks off Southern California in deep-water drift gill nets, the decision brought a big sigh of relief.

“It’s a great feeling to know that NOAA is using science and not political pressure to decide this issue,” said longtime local fisherman David Haworth. “We have just a few people fighting against millions of environmentalists who think taking one of anything is too many: That would be great, but we have to feed the whole world.”

The decision was a blow to Oceana, The Pew Charitable Trusts and other conservation groups that have lobbied for years to close the fishery.

“We’re disappointed that NOAA Fisheries decided to abandon these plans. It’s a long time coming,” said Paul Shively, project director for The Pew Charitable Trusts. “We did a poll (in 2015) that showed overwhelming support with Californians” to implement hard caps on the fishery’s sensitive bycatch.

“This still remains the most harmful fishery on the West Coast when it comes to marine mammals and sea turtles.”

Existing protections working

The proposed hard caps would have forced a seasonal closure if gill nets killed two sea turtles or fin, humpback or sperm whales, or four short-fin pilot whales or bottlenose dolphin over a two-year period.

In 2015, 18 drift gill net vessels landed 66 metric tons of swordfish worth $454,000, according to a report by NOAA — the National Oceanic and Atmospheric Administration. Meanwhile, the U.S. imported 8,386 metric tons of the fish from other countries.

Fishers and National Marine Fisheries Service regulators say protections they’ve instituted since the mid-1990s, when drift gill nets were indiscriminately killing tons of marine animals, have come a long way.

“We increased our net size and that helped (reduce bycatch) a lot,” Haworth said. “What’s very discouraging for us right now is that most marine mammal species are on the increase now. They wanted to shut us down over animals that are doing better. So, it was like, ‘What’s going on here?’ ”

NOAA fishery biologist Jim Carretta, who specializes in creating marine mammal protections, said regulations implemented since the 1990s have greatly reduced gill net damage.

Gill nets are now made with wider mesh to allow larger animals to escape, and are placed 36 feet below the ocean’s surface to avoid marine mammal interaction. They also have acoustic pingers that divert dolphins and other species.

“If you have a bycatch problem, you don’t immediately shut down the entire fishery. You start examining what factors are driving the problem,” Carretta said. “We’ve had great success in reducing bycatch in this fishery. But it’s not going to go to zero.”

Regulators and fishers are also testing new technologies to bring additional protections for bycatch, such as a new deep-set buoy gear and electronic observers on boats to monitor catches.

State Sen. Ben Allen, whose district includes much of the South Bay coast, proposed a bill last year that would hasten the use of deep-set buoy gear and ban gill nets. It remains in committee.

“We already have allowable take numbers for these marine mammals,” Carretta said. “The hard cap levels seemed arbitrary to me. They were not thoroughly steeped in the science behind calculating how much bycatch is sustainable.”

The Marine Mammal Protection Act and the Endangered Species Act also continue to set protections for vulnerable marine animals that were hunted to near-extinction.

‘Redheaded stepchild of fishing’

Mike Conroy, president of West Coast Fisheries Consultants that represents fishers, said he believes the rule would have been overturned in the courts if it had passed.

“Twenty years ago, the drift gill net fishery was the Wild West, but I can’t even remember the last time a turtle was caught,” Conroy said. “(The proposed rule) probably wasn’t enforceable anyway.”

Gary Burke, a veteran drift gill net fisher, also said he hasn’t seen a sea turtle in years.

Shively said government observers should be on board every fishing boat to ensure bycatch is accurately reported. Regulators say that’s not feasible.

“We’re been the redheaded stepchild of fishing,” Burke said. “All fisheries have bycatch. But we’ve done great jobs to limit what we can. We are going to have some, but the question is whether we’re killing too many. That’s why NOAA takes estimates and decides how many can be removed to maintain healthy populations.”

Correction: Due to a reporting error, an earlier version of this story misquoted Paul Shively, project director for The Pew Charitable Trusts. The quote referenced a 2015 poll that found Californians overwhelmingly support putting hard caps on drift gillnet bycatch.