An astronaut photograph, taken from the International Space Station, highlights a recent gigantic plankton bloom in the Black Sea’s eastern half. The Black Sea, a large inland water body that connects eastern Europe and Asia Minor, frequently hosts widespread blooms of phytoplankton during the spring and summer seasons.
Phytoplankton occupy the base of most aquatic food chains and therefore serve as the primary producers in these ecosystems, despite being microscopic in size. The term “phytoplankton” includes several organisms—cyanobacteria, diatoms, dinoflagellates, algae and coccolithophores—that feed larger creatures such as fish and shrimp.
The Black Sea receives contributions of freshwater from several river systems, including the Danube, Dnieper, Dniester and Don, but it’s also connected to the saline Mediterranean and Marmara Seas. These same river systems transport nutrient-filled urban and agricultural runoff to the Black Sea; the nutrients are consumed by phytoplankton and lead to blooms.
Image courtesy of NASA.