Cyclone Phyan-Induced Plankton Community Succession in the Coastal Waters off Goa, India

Effects of the cyclonic storm Phyan, which hit the states of Goa and Maharashtra in western India during 9-12 November 2009, on coastal waters were studied. Mixing induced by the cyclone appreciably affected the vertical thermohaline structure, composition and growth of plankton. The phytoplankton biomass increased by a factor exceeding 4, and a shift in phytoplankton community occurred with diatoms replacing dinoflagellates as the dominant group. A shift in zooplankton dominance from filter-feeders to herbivores and carnivores was also noticed. The results underline the sensitivity of coastal ecosystems to extreme events.