In addition, the records showed that only two species are endemic to waters south of 60 degrees South, suggesting that particular physiological and reproductive adaptations are required for life in the most extreme environments.
The researchers found that gaps in king crab distributions largely coincide with regions of low water temperature, although there are some anomalous absences yet to be explained.
Their findings imply that even relatively small increases in water temperature due to global warming could lead to king crabs moving into new areas.
"Rapidly increasing water temperatures observed along the West Antarctic Peninsula could allow king crabs to spread from the slope of the peninsula to the continental shelf itself," explained Hall.
This could have considerable ecological consequences. King crabs are voracious predators that crush and then feed on their prey, but they and potentially competing predators such as sharks and rays and other predatory crustaceans are largely absent on the high-Antarctic continental shelves.
"The worry is that the sudden appearance of a new predator with few competitors could threaten isolated shelf communities such as those of the Bellingshausen Sea on the west side of the Antarctic Peninsula," said Hall.
The researchers believe that their study provides a baseline against which future changes in the distribution of king crabs expected under global warming can be compared.
|Contact: Dr. Rory Howlett|
National Oceanography Centre, Southampton (UK)