Climate change might have stimulated a plankton bloom that caused thousands of dead fish to wash up along a 3- to 4-kilometre stretch of beach in Thailand's southern Chumphon province, an expert said. Thon Thamrongnawasawat, deputy dean of the Faculty of Fisheries at Kasetsart University, attributed the fish deaths on Thursday to the bloom - a natural occurrence that lowers oxygen levels in the water and causes fish to suffocate. According to local authorities, plankton bloom happen one or two times a year and typically last two to three days.