June 8. Phytoplankton of the Chukchi Sea began to multiply rapidly before the spring has come. Thinning ice algae has provided the necessary sunlight for photosynthesis earlier than it should.
To assess the discovery of scientists from the American Woods Hole Oceanographic Institution, to understand the lives of the Arctic Sea, adjacent to the North Pole. These seas, including the Bering and Chukchi seas, rich in nutrients, and the only thing that limits the growth of phytoplankton — is light. In winter, the surface mounted thick ice sheet that reflects the light, without which the photosynthetic algae can not grow. Phytoplankton forms the basis of all the marine ecosystem, it binds carbon dioxide and sends it up the food chain. And when spring begins a rapid growth of algae, it is felt by all the inhabitants of the sea, from zooplankton to migrating whales, sailing into the northern sea to feed.
So the scientists were surprised when last year found a multimeter winter ice of the Chukchi Sea real "meadows" of phytoplankton. The results of his observations researchers published in the journal
The reason for the early growth of algae ecologists see that the winter ice has thinned by a few meters, and therefore may miss up to half of the water flux. The researchers analyzed the state of the plankton on two 250-kilometer stretch of sea from the open water to the ice pack, and found a huge "green lake", 100 kilometers in diameter and 30 meters deep. Satellites observe phytoplankton could not because it was hidden under the ice.
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Similar pockets of growth of algae have been found along the Arctic shelf. Although researchers sin to global warming and the consequent thinning of the ice, no one knows how long ago began a premature flowering of water and how it is connected with a thin ice. So far, the results of the study suggest that the production of bio-organics in the Arctic waters severely underestimated — at least 10 times, according to scientists, it is rare where in the ocean can be seen as the rapid growth of algae.
On the one hand, we can rejoice that the local phytoplankton so actively recycles carbon dioxide. On the other — is not known how this affects the food chain. If the algae start to grow earlier and pass rush breeding before become active the rest of the food chain, which means that after the phytoplankton can not provide all the food, and among marine animals can begin hunger. However, as is the case in the Arctic ecosystems due to unusual algal blooms, shown by further research.
Ocean blossomed under the ice due to climate change
June 8. The rapid development of phytoplankton caused by changes in the structure of ice due to global warming. Zazelenevshie areas of the ocean off the coast of Alaska and Chukotka are visible even on satellite images.
Scientists have found that the water off the coast of Alaska began to "blossom" under the ice due to the rapid development of phytoplankton. The study is published in the journal Science.
In the summer of 2011, scientists made an expedition to the Chukchi Sea on the icebreaker USCGC Healy, studying the condition of young ice (thickness up to 1.3 m). They moved into the territory covered by ice for 250 miles, while taking a sample of water ice.
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According to the study, the area phytoplankton blooms under the ice stretched for 100 kilometers, the amount of microscopic algae in the sea areas covered by ice, four times more than in the neighboring areas of free water.
The bulk of the phytoplankton is concentrated in the so-called zone of upwelling, where water from the shallow continental shelf is mixed with the flow from the depths of the ocean. The explosive growth of algae is provided by mineral substances which brings colder water from the lower oceanic layers.
Previously, the development of phytoplankton prevented ice cover: ice, snow clad, ill let the sunlight needed for photosynthesis. However, due to global warming the ice began to melt, and emerging on the surface of the deep puddles form unique lenses that allow light to seep through the ice.
Determine the species composition of algae in the samples to scientists helped automated microscope system Imaging FlowCytobot, which alone has processed millions of images of samples of ocean water.