Florida has 8,000 miles of coastline,occupies 59,988 square miles of land, and has an unusually high diversity of toxic or potentially toxic marine and freshwater microalgae. It also has a high diversity of other plant/animal species in marine and freshwater habitats that vary from coral reefs to salt marshes to a unique freshwater system known as the Florida Everglades has many endemic species. The state itself crosses six degrees of latitude and goes from tropical to warm temperate. The toxic species include 27 dinoflagellates (Gymnodinium, Gyrodinium, Gambierdiscus, Prorocentrum, Ostreopsis, Coolia, Dinophysis, Phalacroma, Alexandrium, Gonyaulax, Pfiesteria), 6 flagellates (Chattonella, Fibrocapsa, Heterosigma, Prymnesium, Chrysochromulina), 3 diatoms (Pseudo-nitzschia), and > 15 blue-greens in 9 genera. Of the toxic marine species, 67% are dinoflagellates with about half of those being benthic species. Many of the Florida strains have been shown to be toxic by isolating, culturing and testing for specific toxins. An interesting point about the presence of known toxic species is that the harmful effects are not always realized. For example, a cell count of 7 million Gymnodinium breve cells/L may not kill baitfish that are in the same water, a cell count of 6 million of Pseudo-nitzschia pseudodelicatissima/L may not cause shellfish poisoning and, even Chattonella blooms that produce brevetoxins may not be associated with fish kills or toxic shellfish. Even a toxic species of Alexandrium may not cause PSP. In order to assess public health and environmental risks, presumed toxic species need to be isolated and tested for production of toxins or bioactive compounds such as fatty acids, and there needs to be a long-term HAB monitoring program supplemented with public health information (number of intoxications, symptoms) and aquatic health (fish and invertebrate kills or diseases)data. Florida has such a program for G. breve HABs and is developing a program for other HAB species.