The natural process of eutrophication and disturbances in the biological and qualitative balance of lakes is accelerated by human activities worldwide that interrupt nutrient biogeochemical cycles and effect on the microscopic planktonic algae or phytoplankton that are the main source of organic matter supporting food webs in freshwater Lakes. If growth and density of these algae increased, very fast bloom algae happened. Blooms of algae are increasingly frequent in some lakes (especially shallow and tropically) around the world and are collectively grouped as harmful algal blooms (HABs). Most taste and odors in surface water are organic and derived from algae blooms. Algae growths can be influenced by the pollution from domestic waste, run-off from fertilizer, and animal, domestic, and industrial waste. Blooms are a prime agent of water quality deterioration, including foul odors and tastes, deoxygenation of bottom waters (hypoxia and anoxia), toxicity, fish kills, and food web alterations. Toxins produced by blooms (almost by cyanobacteria) can adversely affect animal (including human) health in waters used for recreational and drinking purposes. Control and management of algae and cyanobacterial and other phytoplankton blooms invariably includes nutrient input constraints, most often focused on nitrogen (N) and phosphorus (P). Together, these many efforts will provide resource managers with the tools needed to develop effective strategies for the management and mitigation of HABs and their frequently devastating impacts on lakes.
