Tiny sea creatures suggest West Antarctic ice cap could melt
September 1st, 2010A study published in the journal Global Change Biology reports the discovery of very similar colonies of bryozoans – animals that anchor themselves to the seabed – in both the Ross and Weddell Seas.
The bryozoans, sometimes called moss animals, are often microscopic as individuals but form colonies that can look like corals or some seaweeds. Those found were unlike others around the current coast of Antarctica.
So,what’s the big deal?
Bryozoans are largely static and their larvae, dispersed by currents, are short-lived and quickly sink. How is it possible that two virtually identical populations came to exist 2400 kilometers apart, separated by the 2 kilometre thick West Antarctic ice sheet?
An article at ABC News in Science quotes lead author David Barnes:
The most likely explanation of such similarity is that this ice sheet is much less stable than previously thought and has collapsed at some point in the recent past. And if the West Antarctic ice shelf has been lost in recent times we have to re-think the possibility of loss in future with climate change.
If the ice were gone a passage would become open through which currents could carry the larvae between the two seas.
Melting of the West Antarctica ice cap would raise world sea levels by between 3.5 and 5 meters. In a brief warm period about 125,000 years ago, world sea levels were about five meters higher than today and temperatures probably at least 4°C warmer.