Oil-like slick washes ashore on beach in Thailand

A mystery oil-like slick washed ashore on a Thai beach, covering swimmers in sticky residue.

The black film resembling engine oil was seen floating in the sea before reaching the shores of Koh Lan island off the coast of Pattaya on August 9.

Footage shows waves depositing the dark clumps on the sand, covering a half-mile stretch of the island's western coast.

Several tourists, including children, emerged from the sea covered in oil stains and rushed to wash the substance off.

Authorities said there have been no reports so far of any adverse health effects.

Pattaya Mayor Poramet Ngampichet said he has dispatched officials to find the source of the slick.

The Department of Marine and Coastal Resources reported the discovery of tar balls at So and Thung Prong beaches, as well as around Thung Prong Port in the Sattahip area.

Navy personnel had reportedly spotted the marine pollution the previous afternoon, though the source remains unknown.

Officials found the black lumps scattered around So Beach and Thung Prong Beach.

Initial tests found the seawater was within coastal quality standards, with no oil film visible on the surface and no foul smell detected.

Officials collected seawater samples for further testing to determine the level of petroleum hydrocarbons as they continue to monitor the coastline.

The public has been urged not to touch the tar balls or oily residue as they could cause skin irritation.

In February, an oil spill from the Panama-flagged cargo ship Sealloyd Arc reached beaches in Phuket after the vessel sank on February 7.

Around 1,700 litres of oil leaked from the ship, with coagulated residue found at Ya Nui Beach and Banana Beach.

Thailand recorded 130 oil spills between 2017 and 2021. Environmental groups warned that such pollution can cause long-term damage to marine ecosystems and wildlife.