Invasive blackchin tilapia spark concern on Pattaya Beach

Authorities have launched an urgent investigation after a large number of invasive blackchin tilapia were discovered along Pattaya Beach, sparking fears over their impact on the local marine ecosystem and the livelihoods of fishermen.

The discovery came to light after a foreign angler, identified only as ‘Start’, cast a net into the sea following reports from peers that the non-native species had been spotted in the area.

To his surprise, the net came up heavy with the fish, prompting him to call for government intervention.

“I’m worried about the ecosystem," the angler said, questioning how a species typically known for freshwater habitats could survive in the sea.

Responding to the concerns, Nattapong Wannapat, head of the Chonburi Provincial Fisheries Office, explained that the recent heavy rainfall likely washed the fish from freshwater sources into the ocean.

"Blackchin tilapia typically prefer stagnant or brackish water," Nattapong said. "They are, however, highly resilient and can survive in saltwater temporarily. Once the weather settles, they usually migrate back to their original breeding grounds."

Surveys have already confirmed significant populations of the invasive fish in several nearby locations, including Klong Na Klua, the waters bordering Laem Chabang and around Loi Island.

Deputy Agriculture and Cooperatives Minister Watcharaphol Khaokham announced yesterday that he has ordered the Department of Fisheries to verify the findings and conduct an immediate sweep of nearby coastal areas.

"The discovery of these fish has caused public anxiety regarding the marine environment at one of our most famous tourist destinations," Watcharaphol stated.

The minister noted that he issued a directive on May 6 for a nationwide survey of the blackchin tilapia outbreak.

He warned that, if the infestation shows signs of spreading further, the ministry will escalate its response with a comprehensive, systematic management plan to eradicate the species.

First imported to Thailand for research purposes in 2010, and reportedly escaping from research labs, blackchin tilapia, which is native to West Africa, has since spread across dozens of provinces, especially in Yisan sub-district of Amphawa district in Samut Songkhram in 2012.

It is a major concern, because its rapid breeding and extreme resilience allow it to decimate local ecosystems by preying on native fish fry and shrimp larvae, threatening the livelihoods of fishermen and the nation's multi-billion baht aquaculture industry.