Harmful Algal Blooms
EO Capability Benefits
Monitoring Harmful Algal Blooms (HABs) through Earth Observation (EO) technologies is critical for safeguarding marine ecosystems. HABs are dense accumulations of algae that can produce toxins, deplete oxygen, and disrupt aquatic food webs. Early detection and monitoring are essential to minimise their ecological, social, and economic impacts.
EO enables the systematic observation of HABs across extensive marine and coastal areas, offering timely insights into their development, extent, and movement. By tracking key indicators such as chlorophyll-a concentration, ocean colour, and sea surface temperature, EO provides a synoptic and continuous view of conditions conducive to bloom formation and proliferation.
EO Capability Description
The presence of Harmful Algal Bloom (HAB) can be detetected and monitored through EO-based observations of biological and physical water properties. Key parameters include surface chlorophyll-a concentration, turbidity, sea surface temperature, and specific ocean colour signatures associated with algal presence.
The primary satellite sensors supporting HAB monitoring include optical and multispectral sensors for detecting chlorophyll-a levels, water turbidity, and identifying algal pigments, hyperspectral sensors for advanced discrimination of algal species and pigment types when available, and thermal infrared sensors to measure water surface temperatures, which influence bloom dynamics.
Data from these sensors are processed using atmospheric correction algorithms, bio-optical models, and anomaly detection techniques to identify areas of elevated algal activity. Chlorophyll-a concentrations are mapped across defined marine and coastal zones, with time series generated to monitor bloom evolution and intensity trends.
The ability to monitor HABs from space provides an essential complement to in situ sampling, allowing for more comprehensive, frequent, and timely assessments of algal bloom dynamics across diverse aquatic environments.
