Cash for a catch: Thai government wages war against invasive blackchin tilapia

BANGKOK: A fish with a black chin has earned a black mark in Thailand, with the country’s government declaring the eradication of the invasive species a national priority on Tuesday (July 16).

The blackchin tilapia, native to Africa, has spread to waters in at least 13 Thai provinces, threatening local aquaculture and biodiversity as it preys on smaller fish and shellfish, according to the Bangkok Post and Pattaya Mail.

In the province of Samut Prakan, farmers have complained that all their catches now consist of the hardy alien fish that can thrive in freshwater, brackish water and seawater.

In a bid to deal with the growing ecological crisis, Thailand’s Prime Minister Srettha Thavisin on July 16 greenlit a plan to turn the fish into fertiliser, with the government offering 15 baht (56 Singapore cents) for every kilogramme of blackchin tilapia caught in Thai waters.

The latest move, announced by the country’s agriculture minister Thamanat Prompow, is expected to spur local fishermen and the public to catch the species, The Nation reported.

Thamanat added that talks are being held with manufacturers to sell the caught fish to make a Thai fermented fish product known as pla ra.

With sterilisation of the fish under consideration as one method to control its population, agencies have also been tasked with studying whether this process could lead the species to mutate. A special committee with experts and representatives of affected areas has also been set up.

On July 15, dozens of the invasive fish surfaced in Bangkok’s Makkasan swamp after officials drained the body of water in preparation for the wet season and a pumping station was switched off, the Bangkok Post reported.

Blackchin tilapia made up about 20 per cent of dead fish found that day, said Bangkok governor Chadchart Sittipunt, who shared a video showing the species being cooked and eaten.

The 72,000sq m swamp, which connects with the Chao Phraya River via canals, is located in the Ratchathewi district in central Bangkok.

Residents armed with fishing nets, baskets, sacks and even fan grilles descended upon the area to catch the fish prized for its delicious meat, according to The Nation.

Some reportedly netted over 30kg of the species within an hour.

One resident told The Nation that he spotted the catching frenzy being live streamed on social media, and decided to join in using fan grilles and plastic basins.

He planned to prepare a feast for his parents, siblings and neighbours.

Thamanat said the fish had first appeared in Thailand many years ago, and efforts to eliminate it had begun in Samut Prakan, Samut Sakhon and Samut Songkhram provinces, according to the Bangkok Post.

Two thousand of the species were originally imported from Ghana in 2010 by agribusiness Charoen Pokphand Foods (CPF), which had been permitted to study the fish for breeding.

The company said the imported fish were disposed off properly, but they started appearing in local waterways in 2012, according to Thai PBS World, which said financial damage to farms was estimated to be between 150 million and 350 million baht.

The food giant has denied causing the invasion.

Based on DNA tests by the authorities, the blackchin tilapia found in the waters of 13 Thai provinces were found to have come from the same parent stock, the Bangkok Post reported.

Harmful invasive species have cost the global economy at least US$423 billion (S$566 billion) annually according to a sweeping 2023 UN report on invasive species, with such flora and fauna playing a key role in 60 per cent of recorded plant and animal extinctions. – The Straits Times/ANN