Causes of Harmful Algal Blooms

This chapter highlights the key role of changes in nutrients; emphasizes estuarine/marine microalgal species, and includes information on some freshwater harmful algal blooms (HAB). It focuses mainly on microalgae and also presents several examples of macroalgae. It explores some suggestions for advancement in the understanding of HAB and nutrients. Physical factors influence both nutrient retention and cell retention. A major question in HAB biogeography is whether there are biotic provinces that are conductive for specific types of HAB species. Climate controls many of the fundamental parameters regulating algal growth, including water temperature, nutrients, light, and grazers, and thus can be expected to influence changes in the species composition, trophic structure, and function of aquatic ecosystems. Anthropogenic nutrient pollution is a common source of the exogenous nutrients. Compositional changes in algal assemblages occur when nutrients change in proportion or form, at all concentration levels, from limiting to super-saturating.