Scientists are tracking a 640 square-kilometer (400 square-mile) bloom of red tide algae lurking off the Gulf Coast, pointing to it as the likely cause of a mass fish kill and several dolphin deaths at the tip of the Florida peninsula. "It looks almost the size of a small state. It really is a large area of bloom," said Billy Causey, superintendent of the Florida Keys National Marine Sanctuary. "I'd have to say that this is the largest red tide bloom that I have ever seen." A red tide is considered a higher-than-normal concentration of a plant-like microscopic algae. The species that usually contaminates the water during Florida Gulf Coast red tides is called Karenia brevis, which produces a toxin that can affect a fish's central nervous system. It also produces a toxin in shellfish, which, if eaten, can cause a person to suffer tingling in the mouth and fingers, loss of coordination, hot and cold flashes and diarrhea. --mor 1424 Local Time 1124 GMT
