Federal investigation delivers more bad news to Bering Sea crab fleet
A Bering Sea survey by federal scientists holds more bad news for crabbers based in Alaska, Washington and Oregon hoping for a recovery in upcoming harvests that fell last year in rock levels.
The results of the Bristol Bay federal king crab investigation are grim, and crabbers have been warned that — for a second year in a row — there may be no fall harvest, according to Jamie Goen, executive director of Alaska. Bering Sea Crabbers.
The new investigation the results, released late last week, show that the population of mature male snow crabs targeted by crabbers has declined by 22% from 2021, which, at 5.6 million pounds, was at the level the lowest in over 40 years. The snow crab population has crashed amid a warming Bering Sea, and the new survey results are expected to lead to an even lower harvest for the upcoming winter season.
Alaska, within the limits of a federal management plan, determines the number of crabs that can be taken based on these surveys, as well as analyzes by state and federal scientists. When more crabs are found in these surveys, harvest levels generally increase. When surveys indicate crab populations are declining, managers typically reduce quotas to give populations a better chance of rebounding. And, when the numbers fall too low, harvests can be stopped.
As recently as 2016, crab harvests from the Bering Sea brought in more than $280 million for a fleet that uses baited steel-frame traps — called pots — on the ocean floor.
Snow crab and king crab have historically been the most important crops for crabs in the Bering Sea, some of which also pursue smaller populations of other species. And expected harvest reductions this year will put some heavily indebted fishermen at risk of financial catastrophe, Goen said.
“We have an emergency,” Goen said. “I’m trying to get Congress to act to help.”
The National Marine Fisheries Service survey raises hopes of improved harvests within three to five years as young snow crabs reach adult size.
“The good news is that we have seen a significant increase in the abundance of immature snow crabs, both male and female,” said Mike Litzow, survey manager and director of the Alaska Fisheries Science Center’s Kodiak Laboratory. “Depending on how many of these young crabs survive to adulthood, that could be a bright spot for the fishing industry in a few years.”
Surveys show long-term decline
The survey is conducted during the spring and summer months. It has been held annually since 1975 except for 2020 when it was canceled due to the COVID-19 pandemic. This year, the scientists worked aboard two chartered fishing boats that depart from Bristol Bay and move slowly west. They catch crabs with nets at 375 sites ranging from 120 to 1,200 feet deep.
Surveys have tracked a long-term decline in Bristol Bay king crab.
Although anglers target mature males, harvesting only takes place if there are also enough mature females found. In 2021, federal researchers estimated only 6.3 million mature female crabs — the lowest number in more than a quarter century. This year, the estimate has risen to 7.3 million. But that was still below the 8.4 million minimum that the Alaska Department of Fish and Game has set as the threshold for allowing harvests.
Scientists say unfavorable ocean conditions appear to be hampering king crab recovery. But figuring out the details has been difficult.
Over the past decade, as the Bering Sea has warmed, in some years the king crab has moved further north. Researchers say one possibility is that young crabs have lower survival rates when mating in these waters. Another possible factor is increased predation, especially by Bristol Bay sockeye salmon, as their populations exploded.
Scientists are also examining the practice of catching undersized crabs and then discarding them, which could result in death. There is also research and debate on the impact, both in past decades and currently, of trawls towed along the bottom by vessels pursuing cod and flatfish species, as well as larger nets deployed by pollock boats which can also touch the bottom.
A former federal biologist, Braxton Dew, in a whistleblower complaint filed in 2021 through Public Employees for Environmental Accountability, alleges that sampling bias and data tampering in some of the investigations for years 1970 “set the stage for collapse” by giving inflated stock estimates. Based on these surveys, fisheries managers approved excessive harvest levels from which crab populations have yet to recover.
Cooler years might help
Snow crab have a shorter life cycle than king crab and their numbers have fluctuated a lot. Crabeaters caught more than 300 million pounds of snow crab during two peak years in the early 1990s. Last year, after the population collapsed, the harvest was reduced to just 5.6 million pounds.
During the warming of the Bering Sea in recent years, there have been large reductions in sea ice in winter, which is vital for the formation of a pool of cold water at the bottom of the sea which provides young snow crabs a refuge from predators such as cod that do not like cold temperatures. .
As the cold pool shrunk dramatically, scientists say cod predation increased and mortality, along with other stresses from warmer water, may have contributed to the implosion of the crab population. of snow.
Researchers are also studying other stresses related to warmer water. The metabolism of crabs, for example, speeds up as temperatures rise, and food supplies may have been insufficient to meet their needs. Famine may have played a role.
Even though the warming Bering Sea has hurt snow crab, salmon scientists say it’s likely given a boost to Bristol Bay sockeye, which generally do better when temperatures rise by a few degrees and returned last summer in record numbers.
As the sea warmed in 2018 and 2019, surveys indicate that more surviving snow crabs have been found farther north than in the past.
Last year, survey results included a more than 99% decline in immature female snow crabs from those found just three years earlier, as well as a 96% decline in males.
This year’s survey estimated that populations of immature females jumped by 3,902%, a 39-fold increase from 2021. Immature males increased by 138%, more than double.
These results suggest that if cooler temperatures continue, snow crab harvests will increase.
But federal fisheries biologists undertaking the survey warn that more warming is expected as climate change spurred by the burning of fossil fuels and other human activities release greenhouse gas pollution.
“We will have another heat wave. Whether it’s a year or five, it’ll come,” said Leah Zacher, a Kodiak-based federal fisheries biologist with the Alaska Fisheries Science Center who helped with the survey. “And the question is – what will happen?”