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Saturday, May 3, 2008

The World's Largest & Deepest Lake, 25-million-Years Old, is in Trouble: A Galaxy Exclusive

Baikal_lake_2 As the oldest, largest and deepest lake on planet Earth, ancient Lake Baikal is known as the “grand dame” of all lakes. UNESCO declared it a World Heritage due to its stunning bio-diversity. Most of its 2500 some odd plant and animal species, including the freshwater seal, evolved in pristine isolation and are found nowhere else on the planet. The Siberian lake contains an enormous 20 percent of the entire world's freshwater, and is large enough to hold all the water in the Great Lakes combined and then some. The lake has yielded many exciting aquatic wonders and likely holds many more undiscovered marvels in its incredibly deep waters. The 25 million year old lake predates the emergence of humans, but its splendor may not outlive us.

Stephanie Hampton, the Deputy Director of the National Center for Ecological Analysis & Synthesis (NCEAS) who has been studying the lake shared with The Daily Galaxy what makes Baikal so exquisite.

“Lake Baikal probably the most beautiful place I've ever been - I'm thinking especially right now of the day I spent on Olkhon Island when the wildflowers were spectacular and the serenity was awe-inspiring. It is the world's most ancient lake with a proliferation of biodiversity that is breathtaking,” describes Hampton affectionately.

“Where I would usually see 2 species of a particular type of crustacean (amphipods, in this case), instead I see 344 species in all shapes and colors and sizes. Many of the unique fish in Baikal resemble deep-sea fishes rather than other freshwater fish that are more closely related to them - with big eyes and spindly bodies. Also, sponge forests are common. If you are surprised that I'm mentioning a sponge forest in a lake, it's for a good reason: they are not that common in lakes!” Hampton notes with enthusiasm, “So here you are in this incredibly cold lake at fairly high latitude, and underwater, this sponge forest looks more like the Caribbean than the subarctic! It is really like a freshwater Galapagos in the midst of Siberia.”

It doesn’t take much prodding to get information out of Hampton when it comes to the lake! Her abounding awe and reverence for one of Mother Nature’s most unique wonders is completely apparent. Unfortunately, according to Hampton and other experts, all this is about to change forever. Global warming has had a strong impact on the lake, and is threatening its incredibly unique life forms that evolved to live only in extreme cold. A multi-generational study involving careful and repeated sampling over six decades was recently reported in the journal Global Change Biology showing that the lake’s temperatures is rising dangerously fast. Hampton, who participated in the study, notes that the lake was expected to be among those most resistant to climate change, due to its tremendous volume and unique water circulation. But unfortunately, that does not appear to be the case.

“So many organisms in and around Lake Baikal have evolved only in Lake Baikal, and they are very well-adapted to an extremely cold environment that is covered by ice for much of the year. More than half of the animals in Baikal are not found anywhere else! Lake Baikal has been around for 25 million years, so there has been plenty of time for organisms to evolve to its special environment - the warming associated with climate change is very abrupt, and it's not clear whether or how these special organisms can adapt to a rapidly warming lake,” Hampton explains.

Already there has been a rise in more common water organisms in the lake—a sight that does not bode well for the lakes original inhabitants.

“We know that Siberia is one of the most rapidly warming regions of the world - the air temperature in Siberia has warmed at a rate that is about twice that of the average global rate of temperature increase. So when we approached this work with the Lake Baikal temperature data, we knew that the lake would have been exposed to a greater ambient temperature increase than lakes in other regions, but I certainly will admit to being surprised that the lake had warmed so rapidly since 1946. Why is it warming so much faster than the air? The answer probably involves ice,” Hampton explains.

“Ice is a very prominent feature of life on Lake Baikal. Ice normally starts taking over the lake in January and it doesn't leave until May or June - so, life goes on in Lake Baikal under ice for nearly half the year! The top predator in the lake, the Baikal seal, raises its pups on ice in the winter in snow caves, fishing for food in the lake water by using holes in the ice. Under the ice, algae (the microscopic plants at the base of the food web) that are found only in Lake Baikal, are well-adapted to achieve their greatest productivity while there is still thick, but clear, spring ice on the lake. So, both the top and the bottom of the food web in Baikal are very well adapted to long icy winters - this dependence on ice by the top and bottom of the food web is not common in lakes.”

She continues, “We know from previous work, published by other researchers, that the ice is staying on the lake for a shorter time period now than it used to. When ice lasted longer in the past, it kept the lake insulated from air temperature changes for a longer portion of the year. Now that there is less ice, the water is warming faster. This is what other researchers also found on Lake Superior just last year. So, we can expect the lake to get warmer and warmer, as the ice lasts for a shorter time each year.”

But what about the humans in the region? Even if the aquatic resident’s of Lake Baikal can’t thrive in the warmer weather, aren’t the nearby human settlements looking forward to a respite from the bitter cold that global warming may offer? Again, Hampton explains that the issue is a lot more complicated than most of us realize.

“Some of the harshest winters of the century occurred within living memory for many Siberians, and it is easy to understand why Russians might welcome a longer growing season in Siberia. However, one big concern, as the air temperature increases, will be the deterioration of infrastructure as permafrost melts and the ground shifts under buildings and around pipes or other structures laid in the ground,” she explains, “Also, there are villages around Lake Baikal that can only be reached by water during the summer and by travel over the ice in winter - when ice is too thin for travel, but too thick for a boat, those villages are cut off from each other and from the main roads, so there will be societal impacts for some of these isolated villages where winter is already a pretty tough time of year.”

In other words, climate change will likely have a negative impact on the human population as well. As far as the lake itself goes, Hampton points out that she’s not alone in her concern.

“Russia, and many people are concerned for its welfare. A conservation organization called the Baikal Environmental Wave received a prestigious Goldman Environmental Prize this year, and there has been good community involvement in environmental issues surrounding the lake in recent years.”

But awareness alone can’t save the grand dame’s biodiversity, nor other fragile habitats around the globe. It will take action too. But what can we ordinary people do to make any kind of real difference? Climate change expert Thomas Reichler, who was not involved in the study, told The Daily Galaxy that combating global warming starts with simple daily choices that everyone makes. You don’t have to change the world all by yourself, just change your own actions and let your example inspire other to do the same, he says. Things as simple as choosing to “drive smaller cars, drive less, and insulate your house well. Things like this can make a difference.”

Original here

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