Occurrence of red tide caused by Karenia mikimotoi (toxic dinoflagellate) in the Southwest coast of India

with the bloom. Relatively high level of inorganic nutrients (ammonia 0.5-9.7 µM, nitrate 1.3-2.9 µM, phosphate 1-2.3 µM, silicate 23.5-39.9 µM) and chlorophyll a (av. 56.8 ± 23.7 mg m -3 ) concentration were observed during the bloom period. Microscopic analysis revealed that the discoloration was caused by an unarmored toxic dinoflagellate, Karenia mikimotoi Miyake & Kominami ex Oda (Karenia, Gymnodiniaceae) belongs to Gymnodiniales, which cause massive fish mortality by releasing hemolytic compounds.