Glacier retreat reduces aquatic biodiversity

Melting glaciers begin to affect the status of aquatic ecosystems much earlier than expected. Reduction of the ice cover half could lead to the disappearance of almost a third species.

Impact of global warming on the environment is most easily seen in high mountain glaciers. Studies have shown that since the mid 1980s, the glaciers of Mexico and South America decreased by 30%. Some of them are melting faster, some — more slowly, it is believed that the Himalayan glaciers will resist is still relatively long. But in 2100, is believed to environmentalists, most small glaciers will disappear.

There is no need to remind you that the glaciers the rivers. Entire ecosystems are due to the great mass of the mountain of ice. At the same time that such ecosystem began to collapse, it is not necessarily the complete disappearance of the glacier. A group of researchers from Denmark, France, Great Britain and the United States found that the extinction begins when the ice melted only half.

Ecologists have investigated the diversity of invertebrates in ponds fed by the glaciers of the Andes of Ecuador, the European Alps and the coastal mountains of Alaska. If the ice cover is reduced by half, then after that disappeared from 9 to 14 species of insects, representing 11% of all the species in the waters of Ecuador, 16% — for the Alps and 38% — for Alaska.

It should be clear that we are talking about animals that live near the glacier, in the upper reaches of mountain streams and rivers. Some of them demonstrate exceptional moodiness when selecting habitats. For example, spring Lednia tumana lives exclusively on a 500-meter interval from the start of the mountain stream, obviously, high fever, which begins below, she absolutely does not fit. The researchers can not yet say why these kinds of as sensitive to the thickness of the ice cover. After the glacier, even much lower, it continues to feed the pond. Apparently, some of the relationships between living organisms and the environment in this case are too deep, and therefore not well understood.

Invertebrates that live in these waters for a long time no attention of science. After all, they form a rather specific and small community, lost against the background of large-scale ecosystems. But they can serve as a sensitive indicator of the state of the glacier, which determines not only the small mountain streams and large rivers. It is possible that larger and seemingly more stable ecosystems are beginning to feel the reduction in glacier long before it will be noticeable "to the naked eye."

Article environmentalists dedicated to the loss of biodiversity of ecosystems due to the melting of glaciers, published in the journal Nature Climate Change.

Prepared according to the Nature News


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