Antarctica is one of the few places which aren’t explored to the limits. Antarctica’s huge glaciers, hard to survive temperature and the remoteness are what cause a burning curiosity, a nagging itch to discover what lies just beyond the horizon. It’s what drives every scientific expedition. It’s the same reflex that has driven William Detrich, a marine and environmental science professor at Northeastern University, to travel to the world’s southernmost continent more than 20 times since 1983 to try to understand how Antarctic fishes thrive in the extremely cold Southern Ocean.
Detrich, Hegyi, and company set out on a six-week journey to find out what global warming was doing to the icefish. Over the span of 10 million years, the species has adapted to Antarctica’s freezing waters by shedding its heat shock response, a protective mechanism that most vertebrates and other organisms have developed to deal with rapid, but transient, elevations of temperature. Instead, Antarctic fishes evolved to survive the extreme cold by producing antifreeze proteins. Detrich wanted to find out how the rapid warming of parts of the Southern Ocean, where temperatures are estimated to increase 2 to 4 degrees Celsius over the next 400 years, would affect the development of the embryos of Antarctic fishes.
He claimed that these fishes have not experienced such temperatures for about 10 million years. They’ve lost traits that one would think were necessary to survive warm temperatures. Detrich suggested that it isn’t possible for these fishes to re-evolve a heat shock response in such a relatively short period of time. He said the reason we should care about the survival of this strange-looking species is that they are critical to the Southern Ocean food web. The decline of Antarctic fishes could deplete the food supply for some seals that feed upon them as part of their diet, in turn disrupting the ecosystem.
Harminder Singh