article: The Guardian
The dispersal of tiny sea creatures in Antarctica has alerted scientists to the vulnerability of Earth’s ice sheets
Bryozoans found in the Ross and Weddell seas were almost identical, meaning the ice sheet that separates them isn’t as ancient as once thought. Photograph: British Antarctic Survey
Bryozoans make unlikely prophets of doom. Nevertheless, scientists believe these tiny marine creatures, which live glued to the side of boulders, rocks and other surfaces, reveal a disturbing aspect about Antarctica that has critical implications for understanding the impact of climate change.
British Antarctic Survey researchers have found the dispersal of these minute animals suggests a sea passage once divided Antarctica 125,000 years ago. The discovery was made for the ongoing Census of Antarctic Marine Life project and involved comparing bryozoans from the Ross and Weddell seas. These two seas are separated by the west Antarctic ice sheet, one of the planet’s largest masses of ice. Bryozoans found in the Ross and Weddell seas should have been fairly different in structure if the sheet had been stable and ancient. The two populations would have slowly evolved in different manners, if the sheet was millions of years old.