Chapter 2 - Harmful algal blooms

Abstract

Harmful algal blooms (HABs) in marine, brackish, and fresh-water environments are caused by a variety of microscopic algae and cyanobacteria. HABs are hazardous and sometimes fatal to human and animal populations, either through toxicity, or by creating ecological conditions, such as oxygen depletion, which can kill fish and other economically or ecologically important organisms. HAB hazards have increased globally since the 1970s because of eutrophication, climate change, species translocations, and the interactions of these influences. Human vulnerability to HABs is greatest in communities that are nutritionally and economically reliant on fishery resources, but locally HABs also cause damage to tourist industries and have health-associated costs. There have been major research advances in the monitoring, detection, modeling, forecasting, prevention, communication, and treatment of HAB events, which have helped mitigate health and economic risks. However, reducing HAB incidents in the future will be challenging, due to heavily entrenched socio-ecological systems of food production and land management where nutrient fluxes are likely to increase.