Antarctic fish might survive ocean warming: study

A species of Antarctic fish might be able to survive the predicted warming of its native waters over the next century if the warming is gradual enough, according to a New Zealand scientist.

University of Canterbury researcher Charlotte Austin tested how the emerald rock cod adapted to warmer waters after being removed from its minus 1.9-degree centigrade habitat below the Antarctic ice.

The fish were able to fully recover from short exposures to temperatures up to 6 degrees centigrade, but long periods of time at 4 degrees centigrade was fatal, Austin said in a statement Thursday.

However, if the temperature increase was gradual, all fish tested survived the 56 days of the experiment at 3 degrees centigrade and were able to successfully digest food, a vital physiological process for survival, she said.

The results provide some optimism for the survival of this species if ocean temperature in Antarctic does not exceed the predicted increase of 2 degrees centigrade over the next century.

Austin said Antarctic cod dominated the Southern Ocean and were vital to the food-web and ecosystem due to a wide range of predators, including whales, orca, seals, penguins and other fish.

Several species have been targeted by humans for commercial fisheries and the sustainability of the largest cod species, the Antarctic toothfish, is a subject of contention.

The adult emerald rock cod is about 170 mm in length, while the Antarctic toothfish could exceed 2 meters when fully grown.