The Heat Is Online

Antarctic seabed ecosystems changing due to light from thinning sea ice

Scientists found marine creatures including deep-sea sponges never seen before in the area below an ice shelf

The Independent (U.K.), Nov. 27, 2017

A team of scientists who found an array of sea life not found before in an area they explored beneath an Antarctic ice shelf believe the dramatic change may be caused by global warming. 

Research divers who inspected the seafloor below the Ross Ice Shelf for the first time in eight years ago said in the past marine creatures here were sparse because it was usually in darkness.

But they think the thinning of the ice shelf explains why this time they found organisms such as deep-sea sponges, sea stars, brittle stars and sea cucumbers, The Washington Post reported.

They suspect the change is due to sunlight now being able to filter through the frozen mass due to climate change – allowing plankton to form and sustain a wider variety of underwater life.

The team of scientist divers - three from Finland and six from New Zealand – are currently camping on the ice shelf near New Harbour in the Ross Sea from where they embark on their underwater expeditions.

Two of the researchers noted how the marine life had changed since the group’s first trip below the frozen mass on a previous venture, one of the group reported.

“Two days ago, [two of the researchers] did the first dive of the year under the ice in crystal clear water, and much to everyone’s surprise, the animal community on the seafloor had changed dramatically since the last visit in 2009,” Finnish scientist Patrick Degerman wrote in a dispatch. “Surprisingly big changes in the coastal seafloor communities have occurred in only a few years."

 “The first diver observations show that the changes can be unexpectedly rapid, even in Antarctica, where everything is expected to happen very slowly due to the low temperature,” he added on the expedition’s Facebook page, 'Science Under the Ice'.

“What used to be a very stable, sparse and food-deprived animal community on the seafloor under the thick ice in New Harbour is now much richer, with more species and higher densities of animals,” Mr. Degerman wrote. “Some species rarely observed at this site now appear to be relatively common.”

The scientists are based at two camps on the Ross Ice Shelf where they will be stationed for six weeks. They are comparing their discoveries to findings made during the previous mission.

 “The aim of this expedition is to explore how climate change will affect the marine biodiversity in Antarctica,” Mr. Degerman said.

“The rich community now observed is most likely a rapid response to the sea ice breaking out two years in a row, resulting in more light and higher productivity in the ecosystem.”

http://www.independent.co.uk/environment/sea-life-changes-beneath-below-antarctic-ross-ice-shelf-global-warming-climate-change-new-harbour-a8076901.html