The main ecological significance of dinoflagellates lies elsewhere, though. They are second only to diatoms as marine primary producers. As phagotrophic organisms they are also important components of the microbial loop in the oceans and help channel significant amounts of energy into planktonic food webs.Dinoflagellates form a large group of flagellate protists. They mainly inhabit in marine water, but some are found in fresh water also. Many are photosynthetic in nature, while some are non photosynthetic also. Dinoflagellates are an important component of the phytoplankton and a good source of food for larger organisms. They also play important roles in the biology of coral reefs. Many dinoflagellates are bioluminescent that is they produce
