What causes red tide?
Red tide occurs when an algae rapidly increases in numbers to the extent that it dominates the local planktonic or benthic community. Such high abundance can result from extensive growth, caused for example by a metabolic response to a particular stimulus (e.g. nutrient levels, or some environmental condition like a change in water temperature, salinity or light intensity), or from the physical concentration of a species in a certain area due to local patterns in water circulation. The similarity of these alga and heterotrophs often make it difficult to identify the precise cause of algal bloom, and to predict its impact on the affected ecosystem.
