Global warming brings crab threat to Antarctica

September 7, 2011
The sea floor around the West Antarctica peninsula could become invaded by a voracious king crab, which is on the march thanks to global warming, biologists reported on Wednesday.

The sea floor around the West Antarctica peninsula could become invaded by a voracious king crab, which is on the march thanks to global warming, biologists reported on Wednesday.

The worrisome intruder is a bright-red deep-sea predator that previously had been spotted only in the Ross Sea, on the other side of .

identified the crustacean just five years ago, bestowing it with the lengthy monicker of Neolithodes yaldwyni Ahyong and Dawson and placing it among the 121 species of .

It is known as an "ecosystem engineer" because it digs into the sea floor to feast on worms and other tiny animals, an activity that in large numbers can have repercussions across the .

A team led by Laura Grange of the University of Hawaii at Manoa lowered a remote-controlled scoutcraft as part of a long-term probe into biodiversity in the waters off the Antarctic peninsula.

They looked at Palmer Deep, a mud-floored basin in the located 120 kilometres (75 miles) from the edge of the .

The robot's camera, trailed over two kilometres (1.2 miles), spotted 42 crabs, all of them at depths lower than 850 metres (2,760 feet), where the water was a relatively balmy 1.4 degrees Celsius (34.5 degrees Fahrenheit).

By extrapolation, the in Palmer's deep -- an area measuring 14 kms (nine miles) long by eight kms (five miles) wide -- could be more than 1.5 million, says Grange.

That density is the same as commercial crab fisheries in Alaska and the British South Atlantic island of South Georgia.

The images gave a glimpse of the kind of damage caused by the foraging crustaceans.

The crabs, their shells measuring roughly 10 centimetres (four inches) across, had dug gashes up to 20 cms (one foot) into the soft ocean floor and thrown up lumps of sediment. The robot also retrieved a pregnant female crab, as proof that the species was reproducing.

None of the crabs was found at shallower depths, where the seas are colder.

The implication is that as global warming heats the frigid coastal-shelf waters, which lie at depths of 400 and 600 metres (1,300 and 1,950 feet), the way will be open for the crustacean to continue its creeping advance.

The evidence from sediment is that no so-called lithodid, or crushing, crabs have inhabited the cold shallow waters of the West for 14 million years.

Previous research has already named the peninsula as one of the most vulnerable regions in the world for global warming. The waters of its continental shelf are warming at the rate of 0.1 C (0.14 F) per decade.

"If N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf within one to two decades," warns the study, published in the British scientific journal Proceedings of the Royal Society B.

Explore further: King crab distributions limited by temperature in the Southern Ocean

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4.3 / 5 (6) Sep 07, 2011
how do these things taste?
5 / 5 (5) Sep 07, 2011
Oh the horror! Global warming is threatening mankind with vast new sources of delicious food.
4 / 5 (8) Sep 07, 2011
Once again we need to stand together to fight global warming and EAT THOSE CRABS! lol
3.7 / 5 (6) Sep 07, 2011
No problem. Just convince the chinese that this crab will increase their virility and it will be on the endangered list in no time.
5 / 5 (1) Sep 07, 2011
New at Red Lobster! Only $15.99!
1 / 5 (1) Sep 07, 2011
This means tahet when we finally win with the global warming, the global chillout will become a threat to the crabs and we will have to save them by well... warming the planet again.

Infinite loop.
1.8 / 5 (5) Sep 07, 2011
This is completely ridiculous. Its one thing to say global warming may cause problems >50 years from now, but the current trend to blame everything on global warming NOW is a joke. Its a fucking 0.03 of a degree rise every year. Clouds must be raping the world with the amount of temperature variation they cause.
5 / 5 (1) Sep 07, 2011
Look like a major business opportunity. They're brilliant eating.
3 / 5 (4) Sep 07, 2011
So crabs return home after 14 million years? Sounds like a reason to be happy. What made them leave back then? That's the real story. This rock we live on never seems to sit still or stay in one ecological state for long. It's almost as if there's no baseline to infer a "normal" from. I bet, once you acknowledge that fact, it's really frustrating to conduct real science. So frustrating you might just deny the dynamic Earth entirely in favor of the human burnt static Earth model.

Seriously though, these things were identified just five years ago and you're already claiming you have enough data to determine a global warming induced migration. Someone needs their funding yanked and editor needs to get canned.
1 / 5 (1) Sep 07, 2011
So they discovered this crab 5 years ago... yet seem to think they know every thing about it already? Are we really so far gone as a species that we assume to know the complexities of nature and it's cycles? Don't get me wrong, I'm certain humans have caused gloabal warming to a degree... but what could we possibly know about it's real effect on the OCEAN? It's huge and vastly unexplored.
5 / 5 (1) Sep 07, 2011
1300 to 1950 feet deep? That's a little deep for a crab pot with a buoy line. Someone should invent a crab pot that will float to the surface when it receives a coded acoustic command. Given current king crab prices, they'd pay for themselves in a hurry. This is a fishery that is overdue for some major automation.
not rated yet Sep 08, 2011
Oh the horror! Global warming is threatening mankind with vast new sources of delicious food.
Except when you consider all other fisheries, warming oceans become less productive overall. For instance:


So try not to celebrate too prematurely...

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