Antarctica Fish Threatened By Climate Change
February 14, 2012

Antarctica Fish Threatened By Climate Change

A Yale-led study of the evolutionary history of Antarctic fish and their "anti-freeze" proteins illustrates how tens of millions of years ago a lineage of fish adapted to newly formed polar conditions — and how today they are endangered by a rapid rise in ocean temperatures.

"A rise of 2 degrees centigrade of water temperature will likely have a devastating impact on this Antarctic fish lineage, which is so well adapted to water at freezing temperatures," said Thomas Near, associate professor of ecology and evolutionary biology and lead author of the study published online the week of Feb. 13 in the Proceedings of the National Academy of Sciences.


Notothenioids account for the bulk of the fish diversity and are a major food source for larger predators, including penguins, toothed whales, and seals. Yale's Peabody Museum of Natural History has one of the most important collections of these specimens in the world.


"The evolution of antifreeze was often thought of as a 'smoking gun,' triggering the diversification of these fishes, but we found evidence that this adaptive radiation is not linked to a single trait, but to a combination of factors," Near said.


"Given their strong polar adaptations and their inability to acclimate to warmer water temperatures, climate change could devastate this most interesting lineage of fish with a unique evolutionary history," Near said.

Yale-affiliated authors of the study are Alex Dornburg, Kristen L. Kuhn, and Jillian N. Pennington.


Image Caption: The development of antifreeze glycoproteins by notothenioids, a fish family that adapted to newly formed polar conditions in the Antarctic millions of years ago, is an evolutionary success story. The three species of fish are an example of the diversity this lineage achieved when it expanded into niches left by fish decimated by cold water environment. Now the same fish are endangered by warming of the Antarctic seas (in order: Chaenodraco wilsoni (common name: spiny icefish); Trematomus newnesi (common name: dusky rockcod); Vomeridens infuscipinnis (common name: antarctic dragonfish). Credit: Courtesy of Yale University


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