Harmful algal blooms (HABs) pollute natural aquatic environment. These blooms are referred to as “red tides” or “green tides,” and are caused by the rapid proliferation of certain species of algae, leading to the formation of dense and visible blooms floating on water surfaces.

These algal blooms are not always harmful but certain species secrete virulent toxins that affects both aquatic ecosystems and human health. The onset and spread of such HABs have increased since the recent years. Scientists, environmentalists, and policymakers are working to find sustainable and practical solutions to counter this menace.

Climate change, nutrient pollution, poor water quality and fluctuations in water quality parameters are the major factors responsible for the proliferation of these harmful algal species. This upsets the ecological balance of aquatic habitat which extend beyond the aquatic habitats.

The adverse effects of HABs on aquatic ecosystems can be very toxic. The excessive growth of harmful algae usually causes oxygen depletion, leading to mortalities of aquatic life. These blooms also affect the food chain and ecosystems thus affecting biodiversity and the loss of species. HABs degrade coral reefs causing damage and irreversible destruction. Human health is also under threat by these harmful algal blooms. They produce toxins such as microcystins and anatoxins which has adverse effects on aquatic and poses a multitude of human health hazards.