RESEARCH IN INDIA

Chapter 1: Algal Blooms

The phenomenon of algal bloom is due to Trichodesmium erythrium, a blue-green algae, is well known on the northwest coast of India. Initiation takes place sometime in the end of February, reaches a peak by the third week of March, and then generally declines by the end of April. The chlorophyll concentration is reported to be on the order of 600 mg/m^3 during the peak. Thus it has a significant contribution in serving as a carbon dioxide sink. In addition, it plays an important role in the enrichment of water by fixing atmospheric nitrogen. Every year the bloom is reported to occur near Goa on the northwest coast of India, besides other localized areas on the west and east coasts. Since the chlorophyll concentration is very high, broad spectral bands like Landsat MSS were found useful in mapping and monitoring the bloom dynamics. The enhanced FCC could reveal the spread of the bloom, and FCC with a combination of band ratio helped in separating the suspended sediments from the algal patch. The role played by the sudden appearance of the bloom is significant from the point of view of biological productivity, carbon dioxide flux (acting as a sink) and nutrient enrichment (nitrogen fixation). The mapping and monitoring can be done on a regular basis with the help of satellite data.