Others feel that it is the combination of increased temperature and lack of rain and wind that cause a bloom to occur. .
Red tides have a deadly effect on sea life. They cause the mass mortality of larger invertebrates and fish that live near the surface and the mammals that breach the surface inside a bloom to breathe. .
In 1996, 149 manatees in Florida died from the effects of the red tide. This was extremely harmful to the manatee population due to the fact that this animal is endangered. Stomach contents showed that the toxin entered through the food chain. Lung tissues also showed that direct contact with a toxic aerosol occurred when the animals broke the surface to breathe. .
Fourteen humpback whales died off the coast of Massachusetts in one month due to eating mackerel that had ingested, through the food chain, the toxic phytoplankton.
Toxic algae has also been linked to the death of more than 400 sea lions of the California coast in 1998. (Higgins, 2000).
Different species of toxic algae are known to cause a wide range of illness in humans. Man is primarily exposed to the naturally occurring toxins produced by harmful algal blooms through the consumption of contaminated seafood products. .
Among the illnesses associated with HAB's the most common are Amnesic Shellfish Poisoning, (ASP), Ciguatera Fish Poisoning, (CFP), Diarrhetic Shellfish Poisoning, (DSP), Neurotoxic Shellfish Poisoning, (NSP), and Paralytic Shellfish Poisoning, (PSP).
Symptoms include complete respiratory arrest, incapacitating diarrhea, paralysis, a sense of euphoria, muscle aches, vomiting, reversal of temperature sensation, short-term memory loss, coma, and even death. As recently as 1987, four victims have died from ingesting toxic mussels from Prince Edward Island, Canada. (Human Illnesses associated with HAB's).
The irritating spray produced by the crashing waves in a red tide area also effect humans.