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Investigations take place in Alaska as 1 billion crabs go missing & In Zanzibar crabs wash up dead on beaches


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In a major blow to America's seafood industry, the Alaska Department of Fish and Game has, for the first time in state history, canceled the winter snow crab season in the Bering Sea due to their falling numbers. While restaurant menus will suffer, scientists worry what the sudden population plunge means for the health of the Arctic ecosystem.

An estimated one billion crabs have mysteriously disappeared in two years, state officials said. It marks a 90% drop in their population.

"Did they run up north to get that colder water?" asked Gabriel Prout, whose Kodiak Island fishing business relies heavily on the snow crab population. "Did they completely cross the border? Did they walk off the continental shelf on the edge there, over the Bering Sea?"

Ben Daly, a researcher with ADF&G, is investigating where the crabs have gone. He monitors the health of the state's fisheries, which produce 60% of the nation's seafood.

"Disease is one possibility," Daly told CBS News.

He also points to climate change. According to the National Oceanic and Atmospheric Administration, Alaska is the fastest warming state in the country, and is losing billions of tons of ice each year — critical for crabs that need cold water to survive.

"Environmental conditions are changing rapidly," Daly said. "We've seen warm conditions in the Bering Sea the last couple of years, and we're seeing a response in a cold adapted species, so it's pretty obvious this is connected. It is a canary in a coal mine for other species that need cold water."

Prout said that there needs to be a relief program for fisherman, similar to programs for farmers who experience crop failure, or communities affected by hurricanes or flooding.

When asked what fishermen can do in this situation, with their livelihoods dependent on the ocean, Prout responded, "Hope and pray. I guess that's the best way to say it."


Zanzibar's government is investigating why thousands of dead swimming crabs have washed up on the beaches of the Tanzanian islands.
Since 28 September, there have been reports of the dead crabs washing ashore at Mtoni, Mizingani and Forodhani public beaches.
The government is urging people not to worry it might be caused by pollution.
Reports indicate climate change leading to an abrupt change in the temperature of the sea might be to blame.
"Some living things like the swimming crabs cannot resist sudden changes in the sea, and they die and wash ashore," Dr Salum Soud, a marine biologist and Zanzibar's director of development and fisheries, told the BBC.
"Ocean waters have layers of temperatures and so the waves force water underneath to go up, thus may cause low oxygen hence the crabs are likely to face death," he added.

The mass deaths of the crabs is not an isolated incident, according to Sheha Mjaja Juma, Director General of the Zanzibar Environment Management Authority (Zema), who told Tanzania's The Citizen paper it had also happened in Seychelles.


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So between climate change (remember the heat dome of last year in the PNW), pollution and overfishing we have some issues
And it's very unlikely that the populations will recover.

The NOAA (National Oceanic and Atmospheric Administration)
““According to the National Oceanic and Atmospheric Administration, Alaska is the fastest warming state in the country, and is losing billions of tons of ice each year — critical for crabs that need cold water to survive.”...

The biomass of crabs up there at St. Lawrence Island [northwest of mainland Alaska in the Bering Sea] didn’t change much. What that suggests is there was a large mortality event or they moved into deeper water beyond our survey or into the Russian shelf,” Foy said, but he sounds skeptical about that last possibility. “The magnitude of biomass could not all have moved without us detecting it. We believe we had a very large mortality event, which points to an extreme event that we have never seen before in the Bering Sea.”

Some good comments from reddit.

For those who don’t know, the Canadian cod fishery used to be extremely profitable. The government wouldn’t tighten “regulations” on how much you could fish at a time, insisting that the declining population would rebound. The fishery collapsed suddenly and has not recovered in over a decade, with annual catches being 70,000 tons rather than the previous two million. So fishermen, next time you assume that regulation is just there to stifle your business and the fish secretly respawn as soon as you leave, think about this precedent.
Slight correction - the Canadian cod fishery collapsed in 1992. While that technically is over a decade, it's really been 30 years and no substantial recovery.

"What's worse is that they didn't drop to 10% of their proper population in 2 years. They dropped to 10% of what it used to be... which was already a fraction of what it should be.

It's a pretty big problem called the shifting baseline. Regulators for example will judge what should be allowed assuming that populations when they started working were the full population. After a couple of shifts you've got 2% of the proper population left and regulators who think that this is 50%. So it's "not that bad".

"I remember a somewhat recent documentary about Tuna overfishing and the effect it would have on the ocean ecosystem. Basically since tuna are an apex predator, by dwindling their numbers down you create an environment where the the tier of fish below them thrive briefly from the lack of predation before they gobble up all the food (fish in tier 3) and there is a massive die off due to lack of food/disease... the end results is you have this proliferation of the bottom tier of the seafood chain: things like clams and mussels cause you don't have enough fish above them on the food chain to keep their numbers in check."

Point is aside from the devastation to the crab market for human consumption, this is a massive disruption to the ocean ecosystem with it's own set of consequences that are to be determined..."

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This stuck out to me...
" the survey revealed that the snow crab population had dropped from an estimated 11.7 billion in 2018, to 1.9 billion in 2022."

Such a massive amount. And now 90% of that 1.9 billion gone....