Warm Chang in Climate

'By comparing these two marine species' we hope to assess how a polar environment shapes responses to environmental stress," says Marsh. "By better understanding how the environment can trigger genetic changes,-- through the genes the polar worm turns on or 'expresses' -- we can gain insight into the potential impact of global warming on marine ecosystems."

"A three-foot-diameter hole needs to be drilled through about seven feet of ice, and then a heated dive hut must be placed over the newly drilled hole in order to prevent it from freezing over -- and to keep the divers happy when they surface out of the seawater, which is at a temperature of minus one degree Celsius,"

 By tracking changes in metabolic activity and locating genes where methylation changes are active, the scientists will be able to pinpoint the types of genes involved in the temperature acclimation process.

Marsh says he hopes the results of the study will shed light on the ability of some Antarctic species to survive current levels of ocean warming.

"The coastal waters around Antarctica have been at very stable temperatures for millions of years," Marsh says. "This low-temperature environment has led to the evolution of many endemic polar marine species. As global sea-surface temperatures rise, temperatures in Antarctica will also increase. For animals that are used to constant cold conditions, even might increases in temperature can have large impacts on survival."

"This information has a huge potential for commercial use in the field of synthetic biology," Marsh notes. "Many of the industrial-scale processes that utilize enzymes require that these proteins are synthetically designed to work efficiently under extreme conditions. In bioreactors, for example, conditions of high heat or high acid are common and require bioengineered proteins for increased stability and catalytic efficiency."

To understand their history, Aronson and a team of palaeontologists collected marine fossils at Seymour Island off the Antarctic Peninsula. Linda Ivany of Syracuse University reconstructed changes in the Antarctic climate from chemical signals preserved in ancient clamshells. As temperatures dropped about 41 million years ago and crabs and fish were frozen out, the slow-moving predators that remained could not keep up with their prey. Snails, once out of danger, gradually lost the spines and other shell armor they had evolved against crushing predators.

Antarctica's coastal waters are warming rapidly. Temperatures at the sea surface off the western Antarctic Peninsula went up 1°C in the last 50 years, making it one of the fastest-warming regions of the World Ocean.

If the crab invasion succeeds, it will devastate Antarctica's spectacular fauna and fundamentally alter its ecological relationships. "That would be a tragic loss for biodiversity in one of the last truly wild places on earth," says Aronson. "Unless we can get control of ship traffic and greenhouse-gas emissions, climate change will ruin marine communities in Antarctica and make the world a sadder, duller place."

But this situation is about to change. "Populations of predatory king crabs are already living in deeper, slightly warmer water," "And increasing ship traffic is introducing exotic crab invaders. When ships dump their ballast water in the Antarctic seas, marine larvae from as far away as the Arctic are injected into the system."