The Salton Sea is California’s largest lake — and one of the most endangered habitats in North America. The sea is extremely salty and getting more so every day. And outbreaks of botulism and lack of oxygen have killed thousands of the birds and fish that call the lake home. Now the lake faces another threat: California is under federal mandate to reduce the amount of water it uses from the Colorado River by the end of this year, and the proposal on the table would virtually dry up the Salton Sea’s major water source — agricultural runoff from the Imperial Valley. Scientists say the lake will be largely evaporated and entirely dead by 2030. That would cause serious erosion and air pollution problems, and would be an ecological disaster for the 400-odd bird species that currently rely on the lake. (Ironically, the Salton Sea is an artificial lake, created when a levee broke on the Colorado in 1905, but it has become increasingly important to birds, as other wetlands areas have been drained and developed.)