Hunting Poisonous Planktons from Space

Toxic algal blooms are not new phenomenon. They have been known to occur throughout human history. It is widely believed that one of the earliest potential documentation of toxic blooms is the Old Testament of the Bible. However, in recent years toxic blooms have become one of the serious environmental problems in coastal areas on a global scale. The global nature of the problem has expanded both in its extent and its public perception over last several decades, and there is a pressing need to develop cost-effective methods with higher spatial and temporal resolutions to deal with. It is in this context that satellite Ocean Color sensors offer potential advantages for bloom detection and monitoring.

In this study we apply our recently developed low backscattering algal bloom detection technique, the Red Band Difference (RBD), to detect various toxic dinoflagellates blooms around the world from space. Detecting and monitoring dinoflagellates blooms is extremely important since they can produce some of the most powerful poisons in the nature. Furthermore, marine toxic blooms are usually caused by dinoflagellate species and they account for approximately 75% of the toxic blooms (Smayda 1997). Since dinoflagellates are well known to migrate vertically, these populations migrate up to the surface for photosynthesis during the day, and consequently, their dense aggregations produce strong bio-optical signals that are detectable by satellites. Here, we present bloom detection results from various regions around the world which confirm the potentials of the RBD technique.