The world’s largest and most biologically diverse lake faces the prospect of severe ecological disruption as a result of climate change. Lake Baikal in Siberia has been designated a World Heritage Site by UNESCO because a high proportion of its fauna and flora is found nowhere else. 

U.S. and Russian scientists have studied the modern-day stresses on the 25-million-year-old lake. It lies next to the Central Siberian Plateau, one of three regions that are currently experiencing the most rapid climate change. (The other two are the Antarctic Peninsula and northwestern North America.) As a result, the lake’s climate has become measurably milder and annual precipitation is expected to increase, causing its ice cover and transparency to change.

As the lake loses its ice, changes in the food web have been documented, beginning with the diatoms that crustaceans depend on. The lake’s fishes will be affected by the decrease in crustaceans and eventually the top predator will suffer. That predator is a freshwater seal found only in Lake Baikal. In their article in BioScience, Marianne Moore and her co-authors note that Baikal is the only lake where both the dominant primary producers and the top predator are highly dependent on ice for both reproduction and population growth. 

The researchers point out that while warmer climate is the principal threat to the lake’s unique biological heritage, the other effects of warming are also threats. Among them are industrial pollution, nutrients from watershed runoffs and the atmosphere, and permafrost thawing.

Russian citizens and their government have demonstrated their determination to protect the lake, taking action when development threatened. The authors of this recent report call for international commitment to limiting climate change and continued monitoring of Lake Baikal by scientists.