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."
Posted by Rebecca Sato.
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