English: The Sea of Azov sits in the south of Eastern Europe, flanked by Ukraine in the north, Russia to the east, the Black Sea in the south and in the west by the Crimean Peninsula. Considered the shallowest sea in the world, it has an average depth of 23 feet (7 meters), with a depth ranging between 3 feet (0.9 meters) and 46 feet (14 meters). The waters of the Sea of Azov are affected by numerous rivers that pour into it, including the Don and Kuban River. The inflow keep salinity low, adds and stirs up sediment, and encourages growth of phytoplankton (microscopic plant-like organisms).

At the western end of the Sea of Azov and extending onto the Crimean Peninsula is a network of shallow, marshy inlets sprawling over roughly 1,000 square miles (2,600 square kilometers). This network of lagoons is known as Syvash (also Sivash or Sivaš). During the summer months, the warmed marsh waters give off unpleasant odors, lending the region the nicknames of “Rotten Sea” or “Putrid Sea.” The shallow lakes and lagoons often appear as shades of pink, orange, and yellow because of the colorful, salt-loving microorganisms that thrive in these hypersaline waters. These lakes and lagoons became so salty because they were formed when seawater surged inland during storms and then was blocked from draining back into the sea. The largest lake, Syvash Lake, typically appears bright pink when viewed from space.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a stunning, clear-sky, true-color image of Lake Azov and Syvash Lake on July 2, 2019. Swirls of sediment and phytoplankton color the water of the Sea of Azov. A long plume of gray smoke from a fire on the Crimean Peninsula blows roughly northeastward across the murky waters.