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.
"Seafloor ecosystems at the bottom of fjords rely on detritus for food, so these Antarctic fjords must be getting some sort of enhanced food input, m
|Contact: Talia S Ogliore|
University of Hawaii at Manoa