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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)
retrieved 13 January 2025
from https://phys.org/news/2025-01-genetic-diversity-alaska-red-king.html

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Traversing the Alaska wilderness, Dick Griffith revealed its possibilities to future generations of adventurers

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Traversing the Alaska wilderness, Dick Griffith revealed its possibilities to future generations of adventurers


Dick Griffith, pictured at his Hillside home in Anchorage on July 22, 2008. (Bob Hallinen / ADN archive)

Roman Dial’s first encounter with Dick Griffith at the Alaska Mountain Wilderness Classic pretty much encapsulated the spirit of the man Dial called the “grandfather of modern Alaskan adventure.”

Griffith invited the 21-year-old Dial, who was traveling without a tent, to bunk with him while rain fell in Hope at the onset of the inaugural race. And then the white-haired Griffith proceeded to beat virtually the entire field of racers — most of whom were 30 years his junior — to the finish line in Homer.

Griffith, who died earlier this month at age 98, was a prodigious adventurer with a sharp wit who fostered a growing community of fellow explorers who shared his yearning for the Alaska outdoors.

Dial was one of the many acolytes who took Griffith’s outdoors ethos and applied it to his own adventures across the state.

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“Someone once told me once that the outdoor adventure scene is like this big tapestry that we all add on to,” Dial said. “And where somebody else is sort of woven in something, we pick up and kind of riff on that. And he added a really big band to that tapestry, and then the rest of us are just sort of picking up where he left off.”

On that first meeting at the race in 1982, Dial and the other Alaska Mountain Wilderness Classic competitors got a sense of Griffith’s humor as well. In a story that is now Alaska outdoors lore, Griffith pulled a surprise move at the race’s first river crossing, grabbing an inflatable vinyl raft out of his pack and leaving the field in his rear view.

“You young guys may be fast, but you eat too much and don’t know nothin’,” Dial recalls Griffith quipping as he pushed off.

“Old age and treachery beats youth and skill every time.”

Kathy Sarns and Dick Griffith cross a river in Wrangell-St. Elias National Park during an Alaska Mountain Wilderness Classic race. (Photo provided by Kathy Sarns)

In those years, Griffith may have been known for his old age as much as anything. But it didn’t take long for the 50-something racing against a much younger crowd to make a mark.

Kathy Sarns was a teenager when she first met Griffith in the early 1980s, and the topic of the Alaska Mountain Wilderness Classic came up.

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“He says, ‘You want to do that race? I think a girl could do that race,’ ” Sarns recalls. “And I’m thinking, ‘Who is this old guy?’ And then he says, ‘If you want to do the race, give me a call. I’ll take you.’ ”

Sarns took up Griffith on the offer and in 1984, she and her friend Diane Catsam became the first women to complete the race.

Dick Griffith leads Diane Catsam and Kathy Sarns through a portion of the Alaska Mountain Wilderness Classic from Hope to Homer. (Photo provided by Kathy Sarns)

Sarns said the adventures “fed his soul,” and were infectious for those who watched Griffith and joined him along the way.

“He motivated and inspired so many people by what he was doing,” Sarns said. “It’s like, well if he can do that, then I guess I could do this.”

By the time Dial and Sarns had met Griffith, he had already established a resume for exploring that was likely unmatched in the state.

In the late 1950s, Griffith walked 500 miles from Kaktovik to Anaktuvuk Pass, passing through the Brooks Range. Later he went from Kaktovik to Kotzebue in what is believed to be the first documented traverse of the range.

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In total, Griffith logged over 10,000 miles in the Alaska and Canadian Arctic. He raced the 210-mile Iditaski multiple times.

Starting in his 60s, Griffith made annual trips north to tackle a 4,000-mile route from Unalakleet to Hudson Bay in northeastern Canada. At age 73, he completed the journey.

“The reason he did a lot of trips by himself is because nobody could keep up,” Dial said.

Dick Griffith, then 65, skis across Big Lake to complete the 200 mile Iditaski race in 1992. Griffith, the oldest competitor in the four-discipline Iditasport competition, left the three other skiers behind him. (Jim Lavrakas / ADN archive)

Born in Colorado, Griffith grew up in rural Wyoming during the Great Depression.

The first Griffith adventure that evolved into lore was the story of how he met his wife, Isabelle.

In 1949, Griffith was plotting a trip from Green River, Wyoming, to Lee’s Ferry, Arizona — a 900-mile trip down the Green and Colorado rivers.

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Isabelle said she’d fund the trip if she could come along. She did, and the two were soon married. After a series of other river adventures, the couple moved to Alaska in 1954.

The couple had two children, son Barney and daughter Kimmer.

John Lapkass was introduced to Griffith through Barney, a friend with whom Lapkass shared outdoor adventures.

Like many, Lapkass connected with Griffith’s wry sense of humor. Griffith would write “Stolen from Dick Griffith” on all of his gear, often accompanied by his address.

In Alaska, Griffith basically pioneered rafting as a form of getting deep into the Alaska backcountry.

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Anchorage’s Luc Mehl has himself explored large swaths of the state in a packraft. An outdoors educator and author, Mehl met Griffith over the years at the barbecues he hosted leading up to the Alaska Wilderness Classic.

Although he didn’t embark on any adventures with Griffith, Mehl was amazed at how much accomplished well into his 80s.

“There are people in these sports that show the rest of us what’s possible,” Mehl said. “It would be dangerous if everybody just tried what Dick did. But there is huge value in inspiration. Just to know it’s a possibility is pretty damn special.”

Griffith continued to explore and compete. He ran his last Alaska Mountain Wilderness Classic at age 81 and continued with rafting trips through the Grand Canyon into his late 80s.

Dick Griffith was a trailblazer in the outdoors/adventure community in Alaska with his early use of rafts to reach deep into the wilderness. (Photo provided by Kathy Sarns)

John Clark’s dad worked with Griffith on Amchitka Island in the early 1960s, assisting with drilling on the Aleutian island before it was used for nuclear testing.

Clark went to high school in Anchorage and regularly joined Griffith on a weekend ski, often tackling the Arctic Valley to Indian traverse.

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Clark described the 21-mile trek through the Chugach Mountains as a “walk in the park” for Griffith, a brisk workout to keep him prepped for bigger adventures.

“I was a teenager and I liked to sleep in,” Clark said. “And he wouldn’t even ask me. He would just come knock on my door at 8 a.m. and say, ‘Get your skis.’ ”

Many of those adventures were done mostly anonymously as a course of habit with friends, some only finding out after the fact what Griffith had accomplished.

“He had the heart of an explorer,” Clark said. “Dick’s exploring 40 years ago would have been with the pure motivation of finding out if he could get from here to there.”

Griffith also was well-known for officiating marriages across the state. He married Sarns and her husband, Pat Irwin, as well as Lapkass and his wife.

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“I don’t know how it started,” Lapkass said. “We weren’t the first but it was kind of special. Everybody sort of wanted him to do the honors.”

He would celebrate the matrimonies with annual “Still Married” parties at his house on the Hillside, open to both those who remained married and even those who didn’t. He continued to officiate marriages until the last few years.

As the community of outdoor enthusiasts grew, the parties at Griffith’s weren’t only held to celebrate marriages. He regularly had big gatherings at his house on Sundays and for the holidays, bringing together his “orphans,” many of whom had no immediate family in the state.

The gatherings were a great time to bring new friends into the fold and rehash old adventures. One story — perhaps more a favorite of guests than the host — involved an instance where Griffith had a bad case of frostbite on his backside after being battered by frigid tailwinds.

“I don’t know how many Thanksgiving or Christmas dinners we had there,” Sarns said. “Always plenty of food and lots of laughter, and that’s where we’d pull out the photos of him recovering in the hospital.”

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In 2012, Alaska author Kaylene Johnson-Sullivan published “Canyons and Ice: The Wilderness Travels of Dick Griffith,” which covered his hundreds of adventures through Alaska and beyond.

The film “Canyons & Ice: The Last Run of Dick Griffith” documented his career and last trip through the Grand Canyon at age 89.

Dick Griffith, pictured in his Anchorage home. (Photo provided by John Clark)

While his achievements were documented in his later years, Lapkass said Griffith’s motivations for being in the wilderness were almost completely internal.

“He was quite an inspiration for a lot of folks,” Lapkass said. “He wasn’t looking for sponsorship, for money or big TV productions or anything. He just felt like doing it. So he did it. And that definitely impressed a lot of people. Because some folks, you know, they want to do stuff, but then they want to let everybody know that they did it.”

As his life went on, Griffith was deeply involved with the Eagle River Nature Center as a board member, trail worker and financial donor.

Perhaps Griffith’s biggest gift to the outdoors community was a dose of self-confidence, a little extra boost to reach that next peak.

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“Everybody that came near him benefited,” Sarns said. “Just because it just made you think outside the box a little more, being around him. You may push yourself maybe a little more, whether it’s an extra mile or an extra 100 miles. For some people it was just, ‘Hey maybe I can just go climb that mountain after all.’ ”





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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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