Antarctic may be invaded by Bathyal King Crabs


Increasing temperatures in the Antarctic are creating conditions ideal for Bathyal King Crabs and if researchers are to be believed, these crabs may soon start contending for resources in the Antarctic marine ecosystems.

According to a new study led by Richard Aronson, professor and head of Florida Tech’s Department of Biological Sciences, the rising temperatures of the ocean west of the Antarctic Peninsula should make it possible for king crabs to move from their current deep-sea habitats to the shallow continental shelf over the course of next few decades.

If this happens, it will be for the first time in millions of years that these crabs will staying playing a role in the marine ecosystem in the Antarctic. 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.

Researchers say that their arrival will have a huge impact on the local ecosystem as creatures on the continental shelf have evolved without shell-crushing predators.

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.

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 continental shelf where the delicate ecosystem flourishes.

The overall effect of the migration of king crabs 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.