Wongamat Beach sea turns green with strong smell as hot weather and calm seas trigger plankton bloom. PATTAYA, Thailand – The plankton bloom phenomenon has returned to Pattaya, with the seawater at Wongamat Beach turning green and emitting a sulfur-like smell starting around noon today. On June 20, reporters observed that the clear green seawater at Wongamat Beach, Pattaya, Chonburi, changed to a dark green color around midday and began to emit a foul sulfur-like odor, raising concerns among local residents and tourists. One tourist said the seawater was still clear and normal in the morning, but after noon, the color started to change and the smell became noticeable. Local fishermen reported seeing green patches in the water since Thursday evening, likely caused by a plankton bloom that formed offshore and drifted into the area on Friday. This phenomenon coincides with the low tide at midday. The unpleasant odor results from the high concentration of plankton, which could affect the beach’s scenery. However, some foreign tourists continued to swim as usual. Authorities have prepared to collect water samples for quality analysis and are monitoring the environmental impact. The bloom is believed to be caused by several consecutive days of intense heat combined with calm sea conditions, which favor the growth of phytoplankton. When plankton multiplies excessively, it causes water discoloration and odors due to natural decomposition processes. Sudden plankton bloom at Pattaya’s Wongamat Beach changes sea color, prompting environmental monitoring. Despite plankton bloom and foul odor, some foreign tourists continue swimming at Wongamat Beach, Pattaya.   Plankton bloom turns Wongamat Beach waters dark green, emitting sulfur-like odor, alarming locals and tourists.