Huge jellyfish swarm appear off eastern Thai coast

Thousands of jellyfish emerged in the sea off eastern Thailand.

Aerial footage shows swarms of the transparent coelenterates peppering the blue-green waters off Trat province at the tail end of the country's rainy season on October 3. They covered a two-mile stretch of sea along Ban Mai Rut Beach.

Suree Pongsai, president of the Mai Rut subdistrict community tourism enterprise, said the jellyfish have been a seasonal tourist attraction for 10 years. They would usually appear in large numbers towards the end of the rainy season as the months become cooler.

She said: 'Many tourists would visit the local communities to see the jellyfish, the sea, the beach, and the fishermen's way of life. The jellyfish are colourful and beautiful, but there are fewer of them than usual this year. They also look paler. 

'The jellyfish emerged a month late, probably because of the monsoon and strong waves. They usually appear in September.'

Visitors can ride boats to view the marine creatures up close.

Though the jellyfish are visible throughout the day, Suree said they are best seen at around 7am when they float toward the surface to soak up some sunlight.

The Mai Rut Sub District Administration Organisation said all tourists must have safety vests during viewing. Boat operators were also warned to cancel trips during poor weather.

Sanya Boonplee, assistant village headman, said the spectacle is expected to last for a few more months before the jellyfish start dying.

He said: 'Community tourism operators are ready to welcome visitors. The fee is 100 baht per person with no time limit for the boat ride.'

Jellyfish blooms occur due for various reasons including favourable environmental conditions, better food availability, and changes in wind or current patterns.

Some jellyfish also follow a reproductive cycle based on environmental cues. They can simultaneously spawn polyps that later become juvenile jellyfish.