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Deep in the frigid east Bering Sea, snow crabs have historically flourished — supporting Alaska’s $160 million annual crabbing industry.
Yet state officials recently sent shockwaves across the industry when they announced there would be no snow crab season this year for the first time — a big blow for commercial crabbers. The species’ population has dropped more than a staggering 80 percent, leaving officials with no choice but to call off the catch, Emma Bryce reported for The Guardian.
What’s behind the dramatic die-off? The theories all point in one direction: warming oceans.
While the news that the snow crab population had lost billions of animals is shocking, the decline didn’t happen overnight, Erin Fedewa, research biologist for the National Oceanic and Atmospheric Administration (NOAA), told The Guardian.
In 2018, an unusually large snow crab population coincided with one of the warmest years on record in the Bering Sea. That lead the population of juvenile snow crabs to plumet in 2019, as they failed to mature in the warmer waters brought by a climate change-driven heatwave.
By 2021, the NOAA survey was even bleaker. All ages of crabs had decreased.
“I just remember being out on the boat and knowing that something was wrong,” Fedewa said. In locations researchers would typically find several thousand snow crabs, they were pulling in only a couple of hundred.
Researchers suspect warming waters led to multiple challenges, causing the population to tumble from 11.7 billion in 2018 to 1.9 billion in 2022. Sea ice melt and warming waters have diminished the crabs’ cold-water habitat, triggering starvation, predation and potentially increased disease. Not only are the animals constrained by a smaller area with fewer resources, but the warmer water also increases the crabs’ metabolism — which requires them to consume more — and is more welcoming to predators like the Pacific cod.
While it will take further research to fully understand what is behind the snow crabs’ drastic decline, scientists have long known that the ocean bears the brunt of global warming — absorbing about 90 percent of the heat generated by rising greenhouse gases. Communities that rely on oceans for their economies and livelihoods are on the frontlines.
Pacific Island nations, for example, are heavily dependent on tuna, contributing more than a third of the global tuna catch. However, ocean warming is altering the habitats of the fish and causing them to move outside the jurisdictions of many of the Pacific Islands, creating an exodus that could cut the average catch by a staggering 20 percent, according to a study led by Conservation International scientist Johann Bell.
Revenue brought in by prized species like the snow crab and bigeye tuna is essential to local economies. For tuna, catch reductions could result in a collective loss of US$140 million per year by 2050 — costing some Pacific island nations’ up to 17 percent of their annual government revenue, according to the study.
Yet these grim predictions are not set in stone. Bell’s study estimates that if countries around the world stick to their emissions reduction commitments under the Paris Climate Agreement and limit global temperature rise to 1.5 degrees Celsius, the average tuna catch will decrease by only 3 percent.
It remains to be seen how cold-water species will fare, even if global temperature rise is limited to 1.5 degrees Celsius. In Alaska, the future of the snow crab industry is unclear. The collapse of the industry didn’t happen overnight, and neither will the recovery.
For their part, researchers in the Bering Sea are working on a stock rebuilding assessment, and continuing to study what is behind the crab’s collapse.
Read the full story here.
Mary Kate McCoy is a staff writer at Conservation International. Want to read more stories like this? Sign up for email updates. Also, please consider supporting our critical work.