SURAT THANI, Thailand – Marine ecologist Dr. Thon Thamrongnawasawat has issued a public warning following confirmed sightings of box jellyfish near Koh Samui and Koh Phangan. The dangerous marine species, known for its potentially deadly sting, has recently been spotted in several coastal areas, prompting local officials to step up monitoring and issue safety advisories.
Dr. Thon, Deputy Dean of the Faculty of Fisheries at Kasetsart University, advised beachgoers to only swim within designated netted zones and to avoid entering the water at dusk or nighttime, when jellyfish are more likely to approach the shore.
Box jellyfish, identifiable by their transparent, cube-shaped bodies and trailing tentacles, are among the most venomous marine animals. Their sting can cause severe pain, shock, cardiac arrest, or even death in extreme cases.
Authorities stressed the importance of immediate first aid in the event of a sting. Victims should pour vinegar (4–6% acetic acid) over the affected area for at least 30 seconds to neutralize unfired stingers. Fresh water, ice, or rubbing the wound should be strictly avoided, as these actions can trigger more venom release. Prompt medical attention is essential.
Local marine and coastal resources officials have begun placing warning signs and maintaining surveillance across high-risk beaches on both islands.
