Commercial Crab Season Delayed In California To Reduce Whale Entanglement Deaths

Image credit: N. Davis/ HIHWNMS/ NOAA Fisheries MMHSRP Permit # 932-1905

By: Kristy Hamilton

Beneath the waves, tens of thousands of threats linger off the coast of California for some of Earth’s largest creatures. Long, vertical ropes that connect heavy crab traps to surface buoys can snag migrating whales as they lounge feed, mouths open wide in the hunt for krill and small fish.

The ropes can get wrapped in their mouth, around their neck, and even anchor an animal by the flipper to the bottom of the ocean, said Catherine Kilduff, a senior attorney with the Center for Biological Diversity. “The heavy crab traps then cinch those ropes tighter as the whales drag the gear, cutting into their skin and making them difficult to disentangle.”

In an effort to prevent such incidents, the California Department of Fish and Wildlife (CDFW) announced a delay to commercial Dungeness crab season until December 15. Normal crabbing season ranges from mid-November/early-December through August/September to avoid peak molting and mating periods.

“Surveys conducted by NOAA and CDFW showed high levels of both species prior to the planned opening,” said Ryan Bartling, a senior environmental scientist at California Department of Fish and Wildlife. “The Director delayed the commercial season because of risk of marine life entanglement, specifically Humpback and Blue whales, which are protected under the ESA and Marine Mammal Protection Act. 

Dungeness crab. Image: CDFW.

The decision wasn’t taken lightly: Dungeness commercial crab fisheries on the West Coast can catch in the realm of 85 million pounds of crab, amounting to $88 million for 530 fishing vessels in California alone.

“California made the right call to delay the commercial Dungeness crab season because of the lingering presence of humpback whales. Unfortunately, other California fisheries remained open and entangled a whale and a sea turtle,” said Kilduff.

A rise in entanglement has scientists concerned, with stark cases hitting the media circuit, including at least three instances of flukeless gray whales off California’s coast, likely due to fishing gear. When the ropes and nets get stuck around their tail, it slowly “saws” off the fluke or cuts off blood circulation until it becomes a dysfunctional appendage.

“These entanglements can injure and kill Endangered Species Act-listed wildlife, increasing the threat of extinction, while also causing suffering of large, long-lived animals,” added Kilduff.

For commercial fisheries, incidental bycatch of marine mammals is allowed as long as it does not compromise the ability of species to maintain optimum sustainable populations, according to the Marine Mammal Protection Act of 1972. For Humpback whales in California, Oregon, and Washington, that amounts to 11 whales per year. Additionally, the Endangered Species Act prohibits the take of an animal listed as endangered or threatened.

Stranding network biologists attempt to cut a line off a humpback whale. Image credit: NOAA.

In 2016, there were 71 cases of entangled whales reported off the West Coast, as well as in neighboring countries that were using US fishing gear, according to NOAA. This is the highest number since records began in 1982.

How the delay will affect dungeness crab season is still uncertain. The delay is good news for whales but not easy for fishermen, a chunk of whose livelihood depends on crab catch.

“At this time it is difficult to calculate the economic consequences to the fleet,” said Bartling. “Opening price, effort, weather and demand variables are at play. We will know more once the season is well underway.”

The real solution may lie with innovations rather than relying on migration timing alone.

Does alternative catch technology exist that doesn’t include crab lines? We chatted with a few experts in the industry to find out.

Ryan Bartling, a senior environmental scientist at California Department of Fish and Wildlife:

“Currently there is no “gear innovation” that is available that can be easily adopted  to replace vertical lines. There are prototypes that are undergoing testing and the Department is working to support innovation with the Dungeness Crab Fishing Gear Working Group among others.”

Catherine Kilduff, a senior attorney with the Center for Biological Diversity:

Yes, ropeless traps and those with timed-release buoys can minimize exposure to the line that stretches from the heavy trap to the buoy. Some California trap fisheries already use galvanic release buoys, that float to the surface after a set number of hours or days so that fishermen can pick them up. Ropeless fishing gear allows fishermen to trigger the release of fishing gear to the surface of the water at any time.

“Changing to a new gear includes a start-up cost and altering current fishing practices, both of which discourage fishermen adoption. But a key term of our lawsuit encourages development of ropeless gear and will allow crabbers to keep using it after the season closes to traditional gear.”

Kristen Monsel, oceans program litigation director for the Center for Biological Diversity. The CBD sued the CDFW in 2017 over the entanglement of creatures protected under the Endangered Species Act. They came to a settlement last March.

“Our settlement agreement helps promote ropeless fishing gear in a couple of ways, including by allowing the use of ropeless gear in waters otherwise closed to commercial Dungeness crab gear starting in 2021, and by requiring the state of California to enact regulations to enable the use of this gear. The gear is still rather expensive, which is one of the reasons why it’s not being used more widely. But the more demand there is, the more that will help drive costs down.

Global Ecology and Conservation study (2019):

“We weigh a total of 16 different gear modifications, social interventions, and regulatory changes in an effort to comprehensively evaluate the management alternatives to reduce conflict between whales and the West Coast Dungeness fishery. We find a small number of alternatives to be uniformly favorable across many cost-weighting scenarios, pointing the way to likely avenues of policy change to minimize future entanglements while protecting the Dungeness fishery.

NOAA's John Moran cuts line entangling a whale. Image credit: NOAA.