Life in the Antarctic Moves More Quickly Than Previously Believed: A Study
Despite its frigid temperatures, life appears to be moving quickly in the Antarctic, as described in a new study regarding the discovery of a surprisingly fast-growing community of glass sponges in an area formerly covered by permanent ice.
With the ice at the surface disappearing, these little-known sponges are launching a seafloor coup, which is surprising given that glass sponges were thought to have very long and slow lives with the boldest estimates suggesting lifetimes of more than 10,000 years.
"By comparing identical tracks video-surveyed by remotely operated underwater vehicle in one of the least accessible parts of the Antarctic, we found two- and three-fold increases in the biomass and abundance of glass sponges, respectively, from 2007 to 2011," said Claudio Richter of the Alfred Wegener Institute in Germany. "This is much faster than any of us would have thought possible."
According to the study's first author, Laura Fillinger, much more important than the sea sponges is the vibrancy of the region's ecosystem.
"A general principle to be learned from our study is that benthic communities are very dynamic, even under the extreme environmental conditions prevailing in the Antarctic," she said. "Only four years ago, the study area was dominated by a species of sea squirt. Now this pioneer species has all but disappeared, giving way to a community dominated by young individuals of a glass sponge."
Going forward, Richter and Fillinger plan to return to this polar site in order to see what happens in the coming years, though they suspect the seafloor there will ultimately reach a climax community similar to those found in shallow and seasonally ice-covered Antarctic waters. However, at this rate, the researchers explain that could happen within decades, not centuries.
What this means for the rest of the Antarctic or the planet is impossible to say, Richter and Fillinger admit, especially since so little is known about glass sponges except that they frequently serve as an important habitat for diverse communities of fish and invertebrates. Though for them, at least, the climactic flux of life appears to be a boon.
"If the alarming rate of ice shelf disintegration continues... glass sponges may find themselves on the winners' side of climate change," the researchers said.