Lifeguards and members of Patong Baywatch discovered the phenomenon after arriving at the beach to begin their patrols yesterday morning.
The phenomenon has inspired locals to turn out in droves to see the red spectacle stretching hundreds of metres along the beach, with some people alarmed by what may have caused it.
Officers from the Department of Marine and Coastal Resources (DMCR) collected some specimens for investigation and took water samples for testing, while lifeguards called in officers from Patong Municipality, who together helped clear the mass of sea urchins from the sand.
“I have never seen anything like it,” said lifeguard Somchai Tiangnoi, who urged all beach-goers beware the sharp thorns or any sea urchins that may still remain on the beach.
“Sea urchins usually live in deep water, and are rarely found near beaches. It is worth thinking about what caused them to end up here.”
Looking for an expert opinion, officers at Patong Municipality’s Public Health Department contacted respected marine biologist Dr Thon Thamrongnawasawat, who serves as the Deputy Dean of the Faculty of Fishery at Kasetsart University in Bangkok.
Dr Thon noted that some species of sea urchins, with short thorns, could be found in some relatively shallow waters, such as near rocks.
However, he pointed out that if deep sea waters had been disturbed, officers could expect to see many more sea urchins wash ashore during high tides in the coming days.
The DMCR this morning identified the sea urchins as ‘Astropyga radiata Leske’, and posted their explanation that the mass of sea urchins washing ashore was nothing more than the result of strong waves during the recent spring tide.