ECOLOGICAL CONSEQUENCES OF HARMFUL ALGAL BLOOMS

Abstract

This book chapter delves into the complex dynamics of harmful algal blooms (HABs) and their far-reaching implications in marine ecosystems. Highlighting the critical role of microscopic planktonic algae as a primary food source for crustaceans, fish, and shellfish, the narrative explores the dual nature of algal blooms, oscillating between advantageous and detrimental impacts on aquaculture and wild fisheries. The chapter underscores the global prevalence of harmful algal blooms, defined by the prolific expansion of specific microalgae, macroalgae or cyanobacteria. Recognizing the escalation of HABs as intricately linked to climate change, nutrient enrichment, and habitat disturbance, the authors elucidate the diverse causes behind their occurrence. Focusing on categories of bloom-forming algae, the chapter details their distinctive characteristics, impacts on aquatic ecosystems, and associated health risks, including various toxins such as paralytic shellfish poisons and neurotoxic shellfish poisons. The discussion further delves into the environmental forces driving HABs, including eutrophication, climate change, and ocean acidification. The consequences of HABs span phycotoxin accumulation, toxin transfer, high biomass blooms, ecosystem disturbance, aerosolized toxins, and localized hazardous blooms. In advocating for a nuanced understanding of the multifaceted contributors to HABs, the chapter emphasizes the need for effective mitigation and management strategies. A holistic approach that considers both anthropogenic influences and broader ecological contexts is crucial to curtail the expanding impact of HABs and restore balance to coastal ecosystems globally