This is the shoreline of the northeastern Caspian Sea — the largest lake in the world — as seen by Korea Aerospace Research Institute’s Kompsat-2 satellite. But it’s suffocating.
In this picturesque image, acquired on 26 September 2012, you can see the mineral-rich land of Kazakhstan’s Mangistau region along the bottom of the image. But what is that green mass all the way up? The answer is algal bloom, caused by heightened levels of phosphorus — found in fertilisers, detergents and unfiltered sewage. Algal boom, caused by industrial and agricultural activity all around the lake, is not good at all. Except for the algae. The ESA explains:
These blooms deplete the amount of oxygen in the water. This causes a reduction in aquatic life and poses a threat to rich fisheries: the Caspian Sea is an important site for sturgeon, which yield roe (eggs) that are processed into caviar.