Mortality typically occurs at cell concentrations of 2.5×10 5 K.
brevis strains involved, toxic components and concentration, stability of extracellular toxins, and exposure routes. Some of these toxicity differences will depend on the differential susceptibility of fish species to exposure to K. Brevetoxin is absorbed directly across the gill membranes of fish or through ingestion of K. Brevetoxins are potent ichthyotoxins and have been responsible for the death of billions of fish over the years. Man, dolphins, manatees, and reptiles are potentially exposed to aerosolized toxins. However, further up the food chain, these toxins can be fatal. Often, the algae and the shellfish that consume them are unaffected. Most species contributing to algal blooms are harmless however, some of the toxins produced by certain species are highly toxic. 2000) taxonomic name for the reclassified Gymnodinium breve and is found almost exclusively in the Gulf of Mexico.
This is a single-celled alga called Karenia brevis and it is usually found in warm saltwater, but it can exist at lower temperatures. The Florida red tide is caused by blooms of a type of microalgae known as a dinoflagellate. Red tides can drastically affect Scandinavian and Japanese fisheries, Caribbean and South Pacific reef fishes, and shell fishing along US coasts. Red tides occur throughout the world, causing a negative impact to natural resources and humans. As red is the most common pigment, the phenomenon is called ‘red tide’. This discoloration is dependent on the species of algae and may be the result of the various pigments, including orange, yellow, blue, green, brown, or red. During this time, the warm, shallow seawater tends to become discolored by the enormous concentration of algae. This usually takes place in the spring and summer in response to an increase in light intensity. In a 2–3 week period, it is possible for each algal cell to produce one million daughter cells. Red tide is a marine event where protistas, including algae and dinoflagellates, go through a tremendous growth period, called bloom. Guy, in Encyclopedia of Toxicology (Second Edition), 2005 Background Information
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