Ponds are some of the most beautiful natural water panoramas, from tiny mountain lakes in the Alps to massive glacier-produced lakes that create gravity-defying scenes of rocks teetering on legs of ice. They’re also often home to a range of ecosystems. Some ponds are shallow enough to swim in, while others contain large predators like crocodiles and platypus. Still, they’re a great place to learn about how the environment works.
The deepest pond in the world is Lake Baikal in southeast Siberia, the second-largest freshwater lake in the world and a Unesco World Heritage Site. The deepest spot in the lake is 1,642 meters, or about five miles below the surface. Lake Baikal is so big it resembles seas in many ways, and it holds more water than all of North America’s Great Lakes combined.
Scientists who study the chemistry of lakes, known as limnologists, are working to understand how this lake functions. One way they do this is to sample a long core from the lake’s bottom and look at its chemical composition over time. They can also use the core to look at the climatic and ecological conditions of the lake in its early years.
At Sargent Mountain Pond, paleolimnologist Jasmine Saros and soil scientist George Jacobson used cores from the lake’s sediment to find out how the pond’s biology changed over time. They studied single-celled microscopic algae called diatoms, which are encased in shells of hard, glass-like silica. They found that after the first diatoms in Sargent Mountain Pond bloomed, tundra plants like sedges and willows slowly established themselves around the lake. As the plants developed, runoff into the pond decreased, and phosphorus from the water slowed to a trickle, leading the lake to become oligotrophic and more acidic.