Why billions of crabs vanished from the Bering Sea and human diets

When you think about beautiful, crisp Alaskan landscapes, you might also picture the bustling activity of the Bering Sea – a hub for seafood like snow crabs.

But what if the landscape is changing, and not just visually? In the last few years, billions of crabs disappeared from the Bering Sea and the event has alarmed both fishermen and scientists alike.

Crabs in the Bering Sea

Picture this: we’re in 2022. Fishermen cast their nets with the hope of reeling in a rich harvest of crabs, but what they find instead is stark emptiness. A baffling number of crabs have vanished from the waters.

Was this a case of overfishing? Scientists were quick to dismiss the theory. The culprit, they believed, was the surprisingly warm water that sent the crabs’ metabolism soaring, leading them to starve to death.

This isn’t an isolated incident. The tragic end of these creatures signals a much broader shift taking place in the region.

As the Bering Sea experiences a significant warming trend, it is becoming less Arctic and more like sub-Arctic regions.

Understanding snow crabs

Snow crabs have long, slender legs and a relatively small, rounded body, with a hard shell that can range in color from light brown to red. They typically grow up to about 6 inches in carapace width, with their legs extending much farther, giving them a spidery appearance.

These crabs are cold-water dwellers, thriving in deep, icy waters, where they scavenge for food like mollusks, small fish, and other marine organisms. Their meat is sweet and tender, making them a sought-after delicacy in the culinary world.

Snow crabs also undergo a molting process, where they shed their old shell and grow a new one, which allows them to increase in size throughout their life.

They hang out in the chilly waters of the North Atlantic and North Pacific, often chilling on the seafloor at pretty deep levels. These crabs are famous for their long, spindly legs and sweet, tender meat, making them a favorite for seafood lovers.

If you spot a snow crab on your plate, it likely came from places like Alaska or the Canadian coasts, where they’re caught in large numbers by commercial fisheries.

Besides being tasty, snow crabs play a key role in their ecosystem. They fit into the marine food web as both predators and prey. They munch on a variety of smaller sea creatures like clams and shrimp, and in turn, they’re hunted by larger animals like certain fish species and seals.

Science behind the change

The findings we’re discussing stem from a recent study by the National Oceanic and Atmospheric Administration (NOAA).

According to the study, warmer, ice-free conditions in the southeast Bering Sea are now roughly 200 times more likely than before humans started pumping planet-warming fossil fuels into the atmosphere.

To put this into perspective, the Bering Sea ecosystem today is drastically different from what it was within the lifetime of a single snow crab fisherman.

The study’s lead author, Michael Litzow, also the director for Alaska’s Kodiak lab for NOAA Fisheries, warns that this trend indicates a future with more very warm years, whereas truly Arctic conditions will become sparse.

Decline of snow crabs in the Bering sea

Snow crabs, a cold-water Arctic species, largely flourish in areas where water temperatures hover below 2 degrees Celsius.

An extraordinary heat wave in 2018-2019, however, proved devastating. As warmer waters sped up the crabs’ metabolism, the supply of food couldn’t keep up, and the crabs starved to death by the billions.

This ecological disaster had a ripple effect, severely distressing Alaska’s fishing industry. The snow crab, a commercially valuable species, contributes up to $227 million a year, according to the NOAA study.

Call for adaptation

“How are we going to do business differently as this process gets worse and worse for the snow crab fishery?” Litzow asked, hinting at the urgency to adapt.

While Litzow remains hopeful for a short-term recovery, citing the recent cold conditions and fresh spawning of young snow crabs, he notes, “the odds are for continued poor conditions.”

The declining population of Alaskan snow crabs in the Bering Sea is indicative of a wider ecosystem change in the Arctic, as seas warm and ice melts.

The ocean around Alaska is becoming inhospitable for several marine species, including the red king crab and sea lions. On the flip side, warmer waters are attracting new species, which pose a threat to the existing ones.

An ecosystem in flux

One notable event that illustrates the changing ecosystem took place during the 2018-2019 heat wave. Pacific cod, which typically can’t survive in the extremely cold habitat of the snow crabs, were able to thrive in the unusually warm waters and they ate a portion of the remaining snow crab population.

Robert Foy, director of the Alaska Fisheries Science Center, highlighted that these vast ecosystem changes are presenting “new challenges and opportunities for fisheries science and management.”

Despite not being involved with the study, Foy spoke about the current efforts to leverage new technologies like drones and artificial intelligence to better respond to environmental changes and ecological responses.

Climate change bellwether

The gravity of what’s happening in the Bering Sea can’t be understated. The Arctic region has warmed four times faster than the rest of the planet, with potentially dire consequences.

Litzow referred to the Bering Sea as a “bellwether” for what’s to come, a chilling reminder of the impacts of climate change.

Before we conclude, it’s crucial to recognize this isn’t just a distant environmental issue. It’s a matter that directly affects people’s livelihoods. It’s time we paid more attention to the changes happening in our world.

To the fisherman casting his net in the Bering Sea, or the consumer buying seafood at the market – this isn’t just a tale of the changing seas, it’s the story of our changing lives.

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