2016-11-14. Vast and Pristine, Russia’s Lake Baikal Is Invaded by Toxic Algae.

posted Nov 16, 2016, 8:59 AM by Alan Gould
By Rachel Nuwer, The New York Times. For GSS Ecosystem Change chapter 7. Excerpt: LAKE BAIKAL, Russia — ...The world’s oldest, deepest and most voluminous lake, Baikal holds 20 percent of the planet’s unfrozen freshwater. It is often described as the world’s cleanest lake. ...that is no longer the case. Senogda’s once pristine sands were buried under thick mats of reeking greenish-black goo. ...The muck, scientists have discovered, follows mass algal blooms at dozens of sites around Lake Baikal’s 1,240-mile perimeter. Confined to shallow water and shores near towns and villages, the problem seems to stem from an influx of untreated sewage — the result of inadequate wastewater treatment. ...Algal blooms threaten iconic freshwater bodies around the world, including the Great Lakes, Lake Geneva, and Lake Biwa in Japan. But Lake Baikal is especially precious: a World Heritage site home to more than 3,700 species, more than half found nowhere else. “People are dumping sewage, waste and rubbish around the lake, creating pretty appalling conditions in some places,” said Anson MacKay, an environmental scientist at University College London. Runoff from fertilizers and other pollutants leads to so-called eutrophication, an excessive growth of algae. These blooms eventually deplete the water of oxygen, suffocating aquatic plants and animals. Russian scientists had assumed that Lake Baikal is simply too vast to suffer such a fate, but recent growth in tourism and development seem to be changing the calculus....  http://www.nytimes.com/2016/11/15/science/lake-baikal-russia-algae.html