Integrated ocean observing system in support of forecasting harmful algal blooms

Harmful algal bloom (HAB) events threaten human health, living marine resources, and ecosystem health. Their occurrence has increased in frequency, duration, and severity over the last several decades. Preventing, controlling, or mitigating the impacts of HABs requires the development of permanent, operational ocean observing systems that continuously provide the data and information necessary for rapid detection and timely forecasts of changes in ecosystem states. Key elements of such observing systems are observations and modeling that must be efficiently linked via data management and communication networks. Building the observing system begins by integrating existing assets, is followed by incorporation of new technologies and knowledge, and is guided by the data and information needs of decision makers. User needs are particularly important for development of operational forecast models and new sensors for measuring required biological (e.g., HAB species abundance) and chemical (e.g., concentrations of HAB toxins) variables in near real time. This article describes operational observing systemrequirements for a HAB forecasting system and current efforts by Regional Associations to develop these observing systems for targeted species in their respective regions.