Understanding Harmful Algal Blooms: Causes, Impacts and Control Measures

Algal blooms are rapid, excessive growth of phytoplankton, which is an escalating threat to aquatic ecosystems, coastal economies, and public health,driven by anthropogenic nutrient enrichment and changing climatic scenarios. This ephemeral phenomenon can trigger a cascade of adverse impacts, such as toxin production, oxygen depletion in water bodies, massive mortalities of aquatic organisms, food chain disruption and even huge economic losses exceeding billions of dollars through aquaculturedevastation, tourism decline and drinking water contamination. Toxin-producing species such as cyanobacteria, diatoms, and dinoflagellates further accelerate mortality through neurotoxins and cytotoxic compounds that often lead to marine shellfish poisoning in humans. The control of HABs spans physical, chemical, and biological methods, each with distinct advantages and limitations. HABs remain a growing and multifaceted threat, which can lead to a cascade of events like ecosystem disruption, human poisoning and huge annual economic losses,so effective management requires moving beyond a single method approach and using integrated systems combining preventive and curative measures across aquatic ecosystems.