Antarctic fjords are climate-sensitive hotspots of diversity in a rapidly warming region

EurekAlert via University of Hawaii at Manoa: Deep inside the dramatic subpolar fjords of Antarctica, researchers from the University of Hawai'i at Mānoa have discovered an unexpected abundance and diversity at the seafloor. During a recent expedition, UH scientists for the first time studied the seafloor communities of glacier dominated fjords along the west Antarctic Peninsula, a region undergoing very rapid climate warming.

The scientists expected to find impoverished seafloor communities highly disturbed by glacial sedimentation, similar to those that have been documented in well-studied Arctic regions. To their surprise, bristle worms, anemones, sea spiders, and amphipod crustaceans abounded in their seafloor photographs, along with a number of sea cucumbers, deep ocean jellyfish and other species. Above the seafloor, the fjord waters were dense with krill.

Scientists suggest that the differences in diversity and abundance between Arctic and Antarctic fjords can be explained by the fact that the subpolar Antarctic is in an earlier stage of climate warming than the Arctic, allowing the Antarctic fjords to sustain high levels of productivity. The Antarctic fjords show little disturbance from glacial melting.

"Our study area along the Antarctic Peninsula is warming as fast as anywhere in the world, and the amazing ecosystems there are changing very quickly," said Craig Smith, a professor of oceanography at UH Mānoa who has been studying how marine ecosystems in the Antarctic are responding to climate warming.

"There appears to be something special about these fjords that stimulates seafloor productivity," said Laura Grange, a researcher at the National Oceanography Centre, University of Southampton, United Kingdom, who was a postdoctoral collaborator at UH Mānoa with Smith during this study....

View toward the NNE from Rothera Research Station (on Adelaide Island) over Laubeuf Fjord. At the centre is Webb Island. On the left are some ice cliffs from the Wormald Ice Piedmont (also on Adelaide Island). The distant mountain behind the ice piedmont is probably the Mount St. Louis Massif (1280 m) on Arrowsmith Peninsula on the Antarctic mainland, 53 km from Rothera. The somewhat darker mountains on the right are on Wyatt Island in Laubeuf Fjord. Shot by Vincent van Zeijst, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license