King crabs threaten Antarctic ecosystem due to warming ocean

September 28, 2015
If climate change allows shell-crushing predators such as king crabs to return to the Antarctic continental shelf, the crabs will likely disrupt the endemic marine fauna. Credit: Photo courtesy of Richard B. Aronson and James B. McClintock

King crabs may soon become high-level predators in Antarctic marine ecosystems where they haven't played a role in tens of millions of years, according to a new study led by Florida Institute of Technology.

"No Barrier to Emergence of Bathyal King Crabs on the Antarctic Shelf," published online in the Proceedings of the National Academy of Sciences, ties the reappearance of these crabs to global warming.

Lead author Richard Aronson, professor and head of Florida Tech's Department of Biological Sciences, said the rising temperature of the ocean west of the Antarctic Peninsula - one of the most rapidly warming places on the planet - should make it possible for king crab populations to move to the shallow continental shelf from their current deep-sea habitat within the next several decades.

Researchers found no barriers, such as salinity levels, types of sediments on the sea floor, or food resources, to prevent the predatory crustaceans from arriving if the water became warm enough.

That arrival would have a huge impact.

"Because other creatures on the continental shelf have evolved without shell-crushing predators, if the crabs moved in they could radically restructure the ecosystem," Aronson said.

The study provides initial data and does not by itself prove that crab populations will expand into shallower waters. "The only way to test the hypothesis that the crabs are expanding their depth-range is to track their movements through long-term monitoring," said James McClintock of the University of Alabama at Birmingham (UAB), another author of the study.

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Because of the warming ocean, king crabs may soon become high-level predators in Antarctic marine ecosystems where they haven't played a role in tens of millions of years. Credit: Dena Headlee/National Science Foundation

In the 2010-11 Antarctic summer, in research funded by the National Science Foundation (NSF), the team used an underwater camera sled to document a reproductive population of the crabs for the first time on the continental slope off Marguerite Bay on the western Antarctic Peninsula. That area is only a few hundred meters deeper than the where the delicate ecosystem flourishes.

The overall effect of the migration of king to shallower waters, explained postdoctoral scientist and study co-author Kathryn Smith of Florida Institute of Technology, would be to make the unique Antarctic ecosystem much more like ecosystems in other areas of the globe, a process ecologists call biotic homogenization.

Such changes, the researchers conclude, would fundamentally alter the Antarctic sea-floor ecosystem and diminish the diversity of marine ecosystems globally.

The data used in the paper were collected during an expedition to Antarctica run jointly by NSF, the Swedish Polar Research Secretariat and the Swedish Research Council. The expedition included scientists from Florida Tech, UAB, the Woods Hole Oceanographic Institution, the University of Gothenburg in Sweden and the University of Southampton in the United Kingdom.

Explore further: Research team sets sail for Antarctica to conduct predatory crab research

More information: No barrier to emergence of bathyal king crabs on the Antarctic shelf, PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1513962112

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10 comments

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Osiris1
not rated yet Sep 28, 2015
Sheesh! Now Antarctica, she got da crabs......who she been with?
jeffensley
4.3 / 5 (6) Sep 28, 2015
Honestly I thought they were suffering from over-harvesting like many other marine species. Knowing this, I'll gladly do my part to keep the population under control by eating them more often.
denglish
1.8 / 5 (5) Sep 28, 2015
Aren't all waters warm relative to the King Crab waters?
maxwell_bean
5 / 5 (5) Sep 28, 2015
Sounds like the King Crabs didn't get the memo from the deniers here....
Whydening Gyre
5 / 5 (6) Sep 28, 2015
More (King) crabs legs for everyone!!
Vietvet
5 / 5 (2) Sep 28, 2015
Honestly I thought they were suffering from over-harvesting like many other marine species. Knowing this, I'll gladly do my part to keep the population under control by eating them more often.


No one is going to be buying King crabs from Antarctica soon, if ever.

denglish
1 / 5 (5) Sep 29, 2015
Sounds like the King Crabs didn't get the memo from the deniers here....

What memo was that?
Osiris1
not rated yet Oct 04, 2015
Hmmm, King crabs in the antarctic. Yep! Good plot for a pilot season of : "Most Dangerous Catch!....Antarctica!!" Just have those captains in the Gulf of Alaska move 'down under' and HQ their boats in Tasmania. THEN we would be able to have some good eatin'..or the Aussies would have some 'King' to throw on their barbies with the shrimp.... Good Eatin' ayy Mate?
Vietvet
5 / 5 (2) Oct 04, 2015
Hmmm, King crabs in the antarctic. Yep! Good plot for a pilot season of : "Most Dangerous Catch!....Antarctica!!" Just have those captains in the Gulf of Alaska move 'down under' and HQ their boats in Tasmania. THEN we would be able to have some good eatin'..or the Aussies would have some 'King' to throw on their barbies with the shrimp.... Good Eatin' ayy Mate?


It's 7,451 kilometers/4,630 miles from Tasmania to Marguerite Bay, too far for even the only reality show I watch. And It's the "Deadliest Catch".
jeffensley
1 / 5 (1) Oct 08, 2015
Sounds like the King Crabs didn't get the memo from the deniers here....

What memo was that?


Since no one answered I'll take a stab. The memo likely states "Any changes to the range or population (increase OR decrease) of any plant, insect, or animal species is ALWAYS directly attributable to Climate Change™ and must be deemed detrimental".

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