Harmful Algal Blooms (HABs) are a national and international problem associated with risks to animal and human health. Several known human syndromes are related to the consumption of shellfish, which concentrate algal toxins in their tissues and thus are of concern to fishery and aquaculture operations. To identify large scale blooms remotely, satellite-based algorithms have been developed for ocean color sensors. While satellite imagery alone cannot distinguish a HAB from non-harmful algae, it can be a useful tool when combined with other ecological data to identify locations of potential HABs.
High frequency monitoring through satellite remote sensing has been beneficial in protecting public and environmental health in several key US waterways. The success of these tools relies on unique optical signatures of specific high biomass HABs, such as those detected during Gulf of Mexico Karenia blooms. Conversely, in Chesapeake Bay a variety of dense algal blooms can appear throughout the year. While these blooms can be detected from satellites, the specific species cannot be determined using only satellite data . The monospecific blooms of Alexandrium monilatum and Margalefidinium polykrikoides that occur in late summer in the southern bay have similar optical properties. In the northern bay, both monospecific and mixed assemblage blooms of dinoflagellates and diatoms occur and these groups cannot be differentiated with current multispectral technologies . These mixed assemblages may be identifiable by combining satellite algorithms with ecological data (e.g., Heterocapsa blooms during the winter) . Several algorithms applied to the Sentinel-3 Ocean and Land Colour Imager (OLCI) have improved our ability to detect and characterize algal blooms at higher resolution. Heuristic models constructed with information regarding the ecological niche of individual species (time of year; bloom succession; salinity, temperature, and nutrient regimes) combined with satellite data can potentially lead to HAB identification. A portable microscope/camera (HABscope) provides near real-time cell counts of Karenia in the Gulf of Mexico. Expanding HABscope technology to new species and extending it to citizen scientist programs in Chesapeake Bay will further support aquaculture and resource management in the region .