A new study found that Alaska red king crabs are more genetically diverse than previously thought, which could be crucial for the species' survival as ocean conditions change.
Researchers came together from Cornell University, the University of Alaska Fairbanks, Alaska Department of Fish and Game and the Alaska Fisheries Science Center, a branch of the National Oceanic and Atmospheric Administration’s Fisheries Service. They sequenced the whole genome of Alaska red king crab across the state for the first time. In the past, studies only researched parts of the crab’s genetic makeup.
Knowing the whole genome of Alaska red king crab helps fishery managers understand more about the crab in specific regions – and what they can do to help increase low populations by using regulation and possible stock enhancements tailored to a particular crab group.
Scientists have long thought that the genetic diversity of the Alaska red king crab fell into three main groups: the Southeast region, the Gulf of Alaska and East Bering Sea regions, and the Aleutian Islands and Norton Sound regions. But new data shows the genetic diversity is even more specific than that.
Researchers recently found that the species should be split into six, maybe even seven, genetically distinct groups. The study noted genetic differences in the crabs in Bristol Bay, the Pribilof Islands, and maybe even between the Chukchi Sea and Norton Sound. It also highlighted that the Aleutian Islands and Norton Sound/Chukchi Sea groups are considered genetically unique populations; therefore it's crucial to prevent overfishing in those areas to keep genetic diversity.
So, why are there so many different Alaska red king crab genetic groups throughout the state? Research shows it’s for several reasons like natural selection and random genetic changes. But it also revealed that the crabs have distinct genetic patterns for local adaptations – meaning they genetically adapt to their environment.
And that’s important. Scientists said having a wider range of genetic diversity can prevent a species from becoming extinct. Still, that doesn’t necessarily mean the Alaska red king crab can handle major environmental changes such as climate change, habitat loss and modern threats from new fishing technologies. Some crab populations are still vulnerable, like the Gulf of Alaska group. The Gulf’s commercial red king crab fishery has remained closed since the population collapsed in 1983.
Scientists said these newfound genetic signs of local adaptations in Alaska red king crab are crucial when studying how they’ll adjust to warming oceans as human-caused climate change continues. It’s not yet known what genetic differences might become important for the crabs’ survival in the future.
