Rapidly melting glaciers could be taking a toll on the diversity of species living in the coastal waters off the Antarctic Peninsula, and the phenomenon could have an effect on the entire seafloor.
Scientists believe increased levels of suspended sediment in the chilly waters is what is causing the loss of diversity, the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research reported. The sediment occurs when global warming causes coastal glaciers to melt, carrying the debris into the seawater.
The western Antarctic Peninsula has seen significant temperature rise over the past half-century, but the impacts of these temperature changes on bottom-dwelling organisms (benthos) has remained largely unstudied. To remedy this, a team of researchers are scrupulously mapping and analyzing the benthos in Potter Cove, which is located on King George Island off the western Antarctic Peninsula. In 1998, 2004, and 2010 divers photographed species at three locations and at different water depths: " the first, near the glacier's edge; the second, an area less directly influenced by the glacier; and the third, in the cove's minimally affected outer edge." They also measured sedimentation rates, water temperatures, and other potentially influential factors. The data suggests some species are extremely sensitive to increased sedimentation rates.
"Particularly tall-growing ascidians like some previously dominant sea squirt species can't adapt to the changed conditions and die out, while their shorter relatives can readily accommodate the cloudy water and sediment cover," said Doris Abele, an AWI biologist and co-author of the study. "The loss of important species is changing the coastal ecosystems and their highly productive food webs, and we still can't predict the long-term consequences."
The findings were published in a recent edition of the journal Science Advances.
