Causes, Human Health Impacts and Control of Harmful Algal Blooms: A Comprehensive Review

Harmful algal blooms (HABs) are increasingly attracting attention all over the world.A diverse set of algal species including diatoms, flagellates, chrysophytes and dinoflagellates can cause harmful blooms, and many produce toxins that harm other organisms and human health.Intensive cyanobacterial blooms, in particular, have been associated with high costs for society due to their potential toxicity.Algal blooms can produce different toxins.These toxins present a long-standing threat to human and environmental health.For example, the severe Karenia bloom of 2005 in the eastern Gulf of Mexico demonstrates the complexities and magnitude of the challenges of managing algal blooms for both environmental and public health.With increasing events and severe impacts of algal blooms on human health, it becomes necessary to monitor and manage toxic algal blooms.Hence this paper presents a review of causes, impacts and control of algal blooms. Causes of HABsUnfortunately, the causes of HABs are uncertain to date.There is no conclusive report available for the causes of HABs.However, some of the factors which are thought to be responsible for causing HABs are succinctly described below. Coastal EutrophicationCoastal pollution resulting from various sources like domestic and industrial effluents is one of the most important factors in the development of HABs.On most occasions, eutrophication due to nutrient enrichment results in algal blooms, some of which are toxic to marine organisms and to humans.Recent research suggests that eutrophication and climate change are two processes that may promote the proliferation and expansion of cyanobacterial blooms [6].Eutrophication or nutrient enrichment can alter 40