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Genetic diversity in Alaska’s red king crab may provide climate change resilience

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Genetic diversity in Alaska’s red king crab may provide climate change resilience


Red king crab on the deck of a research vessel. Credit: NOAA Fisheries / Erin Fedewa

New genetic research on the Alaska red king crab reveals previously undiscovered diversity among different regions, suggesting the species is more resilient to climate change and changing ocean conditions.

Maintaining genetic diversity within and among populations is vital to ensure species are resilient to challenging conditions. Without it, a single disease or set of conditions—such as a prolonged change in ocean acidification—could drive a species to extinction.

Fortunately, new research has revealed more genetic diversity across Alaska’s red king crab populations than originally documented. This suggests that the species will be more resilient in the face of changing conditions like ocean warming. However, any efforts to enhance red king crab populations need to be careful not to affect this genetic diversity.

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King crab in Alaska

Historically, the red king crab fishery was Alaska’s top shellfish fishery. It’s embedded in the culture of Alaska’s working waterfronts and king crabs have been the centerpiece of holiday feasts around the world. However, the red king crab fishery collapsed in the 1980s. Since 1983, most populations have been depressed statewide and the Gulf of Alaska fishery remains closed.

Wes Larson is co-author of the research published in Evolutionary Applications and the genetics program manager at the NOAA Alaska Fisheries Science Center. He reflects, “When it comes to understanding crab biomass declines and how to recover populations, we need to better understand population structure and local adaptation. There are a lot of concerned and invested fishermen, processors, and community members getting more engaged in these issues and it’s propelling new and innovative research.”

To dig into this need, Larson and a team of collaborators embarked on a study to generate whole genome sequencing data on red king crab in different locations across Alaska. The benefit of whole genome sequencing over previous methods is that it’s akin to reading the full story of an organism’s makeup instead of just a chapter or two. This holistic approach offers more robust analysis in order to tease apart similarities and differences between locations.

New genetics research in Alaska

Traditionally, information about commercially important species comes from fisheries-dependent data (collected on commercial fishing vessels) or independent surveys (from scientific research vessels). From these, we gather data on abundance, size, sex, reproductive status, diet, etc.

Genetics tools help to fill in the information gaps from traditional surveys, and can be used to:

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  • Define stock of origin
  • Assess local adaptation
  • Document genetic diversity and inbreeding

Whole genome sequencing builds on past methods by enhancing our ability to detect important differences between populations at finer scales.

Red king crab live in diverse environments—from coastal bays in the north, to open sea shelves in the Bering Sea. They also live in small bays and fjords fed by glacial melt in Southeast Alaska and the Gulf of Alaska. King crab in Alaska generally inhabit the following five regions:

  1. Southeast Alaska
  2. Gulf of Alaska
  3. Aleutian Islands
  4. Eastern Bering Sea
  5. Norton Sound / Chukchi Sea.

Previous genetic studies have hypothesized that king crab from these regions are split into three genetic groups:

  1. Southeast Alaska
  2. Gulf of Alaska / East Bering Sea
  3. Aleutian Islands / Norton Sound.

However, these studies used older genetic techniques, which may not provide the resolution necessary to accurately define genetic structure. The current study reinvestigated the genetic structure of the red king crab in all five regions using high-resolution data derived from whole genome sequencing.

Genetic diversity in Alaska red king crab may provide climate change resilience
Map of collection sites and years of collections colored by regions. Credit: NOAA Headquarters

The results of this study were revealing and informative. Scientists found substantial genetic structure within populations and genetic diversity between regions. In some cases, scientists observed this diversity between populations separated by only a few hundred kilometers.

“Crabs have pelagic larvae, so this is very surprising given the potential for ocean currents to distribute these larvae long distances,” said Larson. “However, these populations do not seem to be mixing and have become genetically isolated.”

Ultimately, the previous hypothesis of three genetic groupings was revised by this whole genome sequencing study. This updated method provided more clarity of fine-scale genetic differences than previous methods. The data indicate that there are six, possibly seven, genetically distinct populations:

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  1. Southeast Alaska
  2. Gulf of Alaska
  3. Aleutian Islands
  4. Bristol Bay
  5. Pribilof Islands
  6. Norton Sound / Chukchi Sea

Data showed previously unrecognized differences between the Gulf of Alaska and East Bering Sea regions. And the East Bering Sea region is split into separate Bristol Bay and Pribilof Islands populations.

Researchers also found that the Aleutian Islands and Norton Sound/Chukchi Sea regions are unique. Data suggests that Norton Sound and Chukchi Sea may be distinct as well. However, further research is required to determine if this is the case.

Scientists attribute this genetic diversity to a combination of factors including populations deriving from different glacial refugia. These are areas that remained ice-free during the lce Age. And more recently, natural selection (genetic changes driven by adaptation) and genetic drift (genetic changes that are random) likely contributed to this diversity. The research documented evidence of local adaptation in most populations.

Fisheries management implications

The scientists’ approach to sequence the whole genome of red king crabs was a more detailed method using orders of magnitude more data than previous studies.

It also confirmed that fisheries are being managed effectively by region in Alaska. For example, crab stocks in the Gulf of Alaska, Aleutian Islands, Bristol Bay, and Pribilofs Islands regions are each managed separately. Prior to this new research, the Bristol Bay and Pribilof Islands were not found to be genetically distinct. This new understanding reinforces that we should continue to manage them separately.

Understanding population structure, and these newly discovered genetic signals of local adaptation, is also important for preventing overfishing on genetically unique populations. And it’s critical to provide information on how local adaptations influence responses to different climatic conditions.

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We may find that some populations have the potential to fare better in future climate conditions that are likely as climate change progresses. Genetics can also reveal shifts in population distribution. Some shifts may already be underway in the Bering Sea as the North Pacific warms.

Finally, with the Gulf of Alaska population being depressed, scientists would expect a higher potential for inbreeding and lower genetic diversity. However, researchers found no evidence of reduced diversity, meaning genetic health did not suffer as the population declined. This foundation of genetic diversity means that genetic factors should not limit recovery.

This research also provides important data that can be used to inform broodstock selection for red king crab enhancement programs. Enhancement programs raise young crabs in hatcheries and release them into the wild to enhance the population.

Given the genetic diversity of red king crab across Alaska, it’s vital to prioritize local broodstock for enhancement before sourcing from elsewhere. This helps to keep genetic diversity intact and ensures that the genetic integrity of locally adapted populations is not jeopardized.

More information:
Carl A. St. John et al, Whole Genome Sequencing Reveals Substantial Genetic Structure and Evidence of Local Adaptation in Alaskan Red King Crab, Evolutionary Applications (2024). DOI: 10.1111/eva.70049

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Genetic diversity in Alaska’s red king crab may provide climate change resilience (2025, January 13)
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Alaskans brave the cold, wind to plunge into Goose Lake for Special Olympics Alaska

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Alaskans brave the cold, wind to plunge into Goose Lake for Special Olympics Alaska


ANCHORAGE, Alaska (KTUU) – At Saturday’s 17th Annual Polar Plunge for Special Olympics Alaska, participants jumped into Goose Lake’s chilly water for a cause.

“The wind today, it’s a cold one,” the organization’s President and CEO, Sarah Arts, said.

More than 800 people came out to jump into the lake, she said. They exceeded their fundraising goal by late morning.

She said it means a lot to the athletes to know that the community is behind them.

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“Inclusion is such a big part of what we do, and sport is a universal language. And through sport, everyone can be included. And it’s so amazing to see the community out here,” Arts said.

She said there were hot tubs for participants to warm up in afterward they jumped into the lake.

“I have to give some shout-outs to South High School Partners Club. Those students had some very creative plunges. A couple of face plants, belly flops. We had a back flip. So, they’re really getting creative today,” she said.

See a spelling or grammar error? Report it to web@ktuu.com

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In Alaska’s warming Arctic, photos show an Indigenous elder passing down hunting traditions

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In Alaska’s warming Arctic, photos show an Indigenous elder passing down hunting traditions


KOTZEBUE, Alaska (AP) — The low autumn light turned the tundra gold as James Schaeffer, 7, and his cousin Charles Gallahorn, 10, raced down a dirt path by the cemetery on the edge of town. Permafrost thaw had buckled the ground, tilting wooden cross grave markers sideways. The boys took turns smashing slabs of ice that had formed in puddles across the warped road.

Their great-grandfather, Roswell Schaeffer, 78, trailed behind. What was a playground to the kids was, for Schaeffer – an Inupiaq elder and prolific hunter – a reminder of what warming temperatures had undone: the stable ice he once hunted seals on, the permafrost cellars that kept food frozen all summer, the salmon runs and caribou migrations that once defined the seasons.

Now another pressure loomed. A 211-mile mining road that would cut through caribou and salmon habitat was approved by the Trump administration this fall, though the project still faces lawsuits and opposition from environmental and native groups. Schaeffer and other critics worry it could open the region to outside hunters and further devastate already declining herds. “If we lose our caribou – both from climate change and overhunting – we’ll never be the same,” he said. “We’re going to lose our culture totally.”

Still, Schaeffer insists on taking the next generation out on the land, even when the animals don’t come. It was late September and he and James would normally have been at their camp hunting caribou. But the herd has been migrating later each year and still hadn’t arrived – a pattern scientists link to climate change, mostly caused by the burning of oil, gas and coal. So instead of caribou, they scanned the tundra for swans, ptarmigan and ducks.

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A lifetime of hunting

Caribou antlers are stacked outside Schaeffer’s home. Traditional seal hooks and whale harpoons hang in his hunting shed. Inside, a photograph of him with a hunted beluga is mounted on the wall beside the head of a dall sheep and a traditional mask his daughter Aakatchaq made from caribou hide and lynx fur.

He got his first caribou at 14 and began taking his own children out at 7. James made his first caribou kill this past spring with a .22 rifle. He teaches James what his father taught him: that power comes from giving food and a hunter’s responsibility is to feed the elders.

“When you’re raised an Inupiaq, your whole being is to make sure the elders have food,” he said.

But even as he passes down those lessons, Schaeffer worries there won’t be enough to sustain the next generation – or to sustain him. “The reason I’ve been a successful hunter is the firm belief that, when I become old, people will feed me,” he said. “My great-grandson and my grandson are my future for food.”

That future feels tenuous

These days, they’re eating less hunted food and relying more on farmed chicken and processed goods from the store. The caribou are fewer, the salmon scarcer, the storms more severe. Record rainfall battered Northwest Alaska this year, flooding Schaeffer’s backyard twice this fall alone. He worries about the toll on wildlife and whether his grandchildren will be able to live in Kotzebue as the changes accelerate.

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“It’s kind of scary to think about what’s going to happen,” he said.

That afternoon, James ducked into the bed of Schaeffer’s truck and aimed into the water. He shot two ducks. Schaeffer helped him into waders – waterproof overalls – so they could collect them and bring them home for dinner, but the tide was too high. They had to turn back without collecting the ducks.

The changes weigh on others, too. Schaeffer’s friend, writer and commercial fisherman Seth Kantner grew up along the Kobuk River, where caribou once reliably crossed by the hundreds of thousands.

“I can hardly stand how lonely it feels without all the caribou that used to be here,” he said. “This road is the largest threat. But right beside it is climate change.”

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Follow Annika Hammerschlag on Instagram @ahammergram.

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The Associated Press receives support from the Walton Family Foundation for coverage of water and environmental policy. The AP is solely responsible for all content. For all of AP’s environmental coverage, visit https://apnews.com/hub/climate-and-environment



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Trump signs bills to ease way for drilling and mining in Arctic Alaska

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Trump signs bills to ease way for drilling and mining in Arctic Alaska


An access road runs between the community of Kobuk and the Bornite camp in the Ambler Mining District, on July 24, 2021. The area has been explored for its mineral potential since the 1950s, and contains a number of significant copper, zinc, lead, gold, silver and cobalt deposits. (Loren Holmes / ADN)

President Donald Trump has signed bills nullifying Biden-era environmental protections in the Arctic National Wildlife Refuge and in Northwest Alaska in an effort to promote oil and mining activity.

The actions were a win for Alaska’s congressional delegation, which sponsored the measures to open opportunities for drilling in the refuge and development of the 200-mile road through wilderness to reach the Ambler mineral district.

The actions are part of Trump’s effort to aggressively develop U.S. oil, gas and minerals with Alaska often in the limelight.

Potential drilling in the refuge and the road to minerals are two of the standout issues in the long-running saga over resource development in Alaska, with Republican administrations seeking to open the areas to industry and Democratic administrations fighting against it.

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The signings were a loss for some Alaska Native tribal members and environmental groups that had protested the bills, calling them an unprecedented attack against land and wildlife protections that were developed following extensive public input.

An Alaska Native group from the North Slope region where the refuge is located, however, said it supported the passage of the bill that could lead to oil and gas development there.

One of the bills nullifies the 2024 oil and gas leasing program that put more than half of the Arctic refuge coastal plain off-limits to development. The former plan was in contrast to the Trump administration’s interest in opening the 1.5-million-acre area to potential leasing.

The federal government has long estimated that the area holds 7.7 billion barrels of “technically recoverable oil” on federal lands alone, slightly more than the oil consumed in the U.S. in 2024. The refuge is not far from oil infrastructure on state land, where interest from a key Alaska oil explorer has grown.

Two oil and gas lease sales in the refuge so far have generated miniscule interest. But the budget reconciliation bill that passed this summer requires four additional oil and gas lease sales under more development friendly, Trump-era rules.

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Voice of Arctic Iñupiat, a group of leaders from tribes and other North Slope entities, said in a statement that it supports the withdrawal of the 2024 rules for the refuge.

The group said cultural traditions and onshore oil and gas development can coexist, with taxes from development supporting wildlife research that support subsistence traditions.

“This deeply flawed policy was drafted without proper legal consultation with our North Slope Iñupiat tribes and Alaska Native Corporations,’ said Nagruk Harcharek, president of the group. “Yet, today’s development shows that Washington is finally listening to our voices when it comes to policies affecting our homelands.”

The second bill that Trump signed halts the resource management plan for the Central Yukon region. The plan covered 13.3 million acres, including acreage surrounding much of the Dalton Highway where the long road to the Ambler mineral district would start before heading west. The plan designated more than 3 million acres as critical environmental areas in an effort to protect caribou, salmon and tundra.

The bills relied on the Congressional Review Act, which gives Congress a chance to halt certain agency regulations while blocking similar plans from being developed in the future.

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U.S. Rep. Nick Begich and Sens. Lisa Murkowski and Dan Sullivan attended the signing in the White House.

“We’ve known the road to American prosperity begins in Alaska; the rest of America now knows that as well,” Begich said in a post on social media platform X.

Begich introduced the measures. Murkowski and Sullivan sponsored companion legislation in the Senate.

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They were part of five bills Trump signed Thursday to undo resource protections plans for areas in Montana, North Dakota and Wyoming, using the Congressional Review Act.

Trump last week also signed a bill revoking Biden-era restrictions on oil and gas activity in the National Petroleum Reserve-Alaska, another Arctic stretch of federal lands west of the refuge. That measure was also sponsored by the Alaska delegation.

The Wilderness Society said in a statement Thursday that the bills destabilize public lands management.

“Americans deserve public lands that protect clean air and water, support wildlife and preserve the freedom of future generations to explore,” said the group’s senior legal director, Alison Flint. “Instead, the president and Congress have muzzled voices in local communities and tossed aside science-based management plans that would deliver a balanced approach to managing our public lands.”

Alaska tribal members criticize end of Central Yukon plan

The Bering Sea-Interior Tribal Commission, consisting of 40 Alaska tribes, said in a statement Thursday that it condemns the termination of the Central Yukon management plan using the Congressional Review Act.

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The action dissolves more than a dozen years of federal and tribal collaboration, the group said.

The termination of the Central Yukon plan will hurt tribes that hunt caribou and other subsistence foods, the group said.

“On the heels of the seventh summer without our Yukon River salmon harvest, we are stunned at the idea our leaders would impose more uncertainty around the management of the lands that surround us,” said Mickey Stickman, former first chief of the Nulato tribal government. “The threat of losing our federal subsistence rights, and confusion over how habitat for caribou, moose, and salmon will be managed, is overwhelming.”

After the signing, federal management of the Central Yukon region will revert back to three separate old plans, removing clarity for tribes and developers and requiring the Bureau of Land Management to start again on a costly new plan, the group said.

“This decision erases years of consultation with Alaska Native governments and silences the communities that depend on these lands for food security, cultural survival, and economic stability,” said Ricko DeWilde, a tribal member from the village of Huslia, in a statement from the Defend the Brooks Range coalition. “We’re being forced to sell out our lands and way of life without the benefit of receiving anything in return.”

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