The finding reveals a new consequence of the Arctic’s warming climate and provides an important clue to understanding the impacts of a changing climate and environment on the Arctic Ocean and its ecology.
Thanks to a NASA-sponsored expedition to the Arctic Ocean in the summers of 2010 and 2011, scientists have found an area underneath the sea ice, which is richer in microscopic marine plants, essential to all sea life, than any other ocean region on the Earth.
The expedition, called ICESCAPE (Impacts of Climate on EcoSystems and Chemistry of the Arctic Pacific Environment), explored the waters in the Beaufort and Chukchi seas along Alaska’s western and northern coasts using optical technologies.
After punching through three-foot thick sea ice, scientists uncovered the single-celled microscopic plants called phytoplankton, which are the base of the marine food chain. Earlier, it was believed that these plants grew in the Arctic Ocean only after the sea ice had retreated in the summer. Now, after the discovery, scientists have come to the conclusion that the thinning Arctic ice is allowing sunlight to reach the waters under the sea ice, catalyzing the plant blooms where they were observed.
The phytoplankton were extremely active, doubling in number more than once a day. Blooms in open waters grow at a much slower rate, doubling in two to three days. These growth rates are among the highest ever measured for polar waters. Researchers estimate that phytoplankton production under the ice in parts of the Arctic could be up to 10 times higher than in the nearby open ocean.
Fast-growing phytoplankton consume large amounts of carbon dioxide. The study concludes that scientists will have to reassess the amount of carbon dioxide entering the Arctic Ocean through biological activity if the under-ice blooms turn out to be common.
The discovery of these previously unknown under-ice blooms also has implications for the broader Arctic ecosystem, including migratory species such as whales and birds. Phytoplankton are eaten by small ocean animals, which are eaten by larger fish and ocean animals, NASA’s web site reads.