File:Indian Ocean from Bagamoyo.jpg

English: Among the tropical oceans, the western Indian Ocean hosts one of the largest concentration of phytoplankton blooms in summer, due to the strong monsoon winds. The monsoonal wind forcing leads to a strong coastal and open-ocean upwelling, which introduces nutrients into the upper zones where sufficient light is available for photosynthesis and phytoplankton production. These phytoplankton blooms support the marine ecosystem, as the base of the marine food web, and eventually the larger fish species. Research indicates that increasing ocean temperatures are taking a toll on the marine ecosystem. A study on the phytoplankton changes in the Indian Ocean indicates a decline of up to 20% in the marine plankton in the Indian Ocean, during the past six decades.