BANGKOK – Thailand has netted more than 1.3 million kg of highly destructive blackchin tilapia fish, the government said on Sept 3, as it battles to stamp out the invasive species.

Shoals of blackchin tilapia, which can produce up to 500 fry at a time, have been found in 19 Thai provinces, damaging ecosystems in rivers, swamps and canals by preying on small fish, shrimp and snail larvae.

As well as the ecological impact, the government is worried about the effect on the kingdom’s crucial fish-farming industry.

About 1,332,000kg of blackchin tilapia were caught from February to Aug 28 – 590,840kg from natural water sources and 743,550kg from breeding ponds, Mr Nattacha Boonchaiinsawat, vice-president of a parliamentary committee set up to tackle the spread of the fish, told AFP.

“We talked to local residents and found out that the spread of tilapia has got worse – they found them in small canals, which was not the case before,” he said.

The outbreak of tilapia will cost the Thai economy at least 10 billion baht (S$382.3 million), Mr Nattacha said.

The fish, native to West Africa, were first discovered in Thailand’s rivers in 2010 before spreading rapidly in 2018, and are now also found in the US state of Florida and in the Philippines.

In July, the Thai government declared the eradication of the species a national priority and began encouraging people to consume the fish.

Promotional activities in central Phetchaburi province advertised tilapia-based fish sauces and sausages.

Restaurants have also increasingly used the fish in cuisine, fried with garlic or sun-dried.

It remains unclear how the fish arrived in Thailand, but local media reports have said they could have been imported by a company from Ghana in 2010.

A parliamentary investigation is under way to determine the cause of the infestation, Mr Nattacha said.

The Thai government has encouraged locals to catch the fish, offering to pay people 15 baht per kg.

It has also designated 75 vending areas around the country where the fish can be sold.

The authorities have released predator species to hunt down the tilapia and are also developing genetically modified blackchin tilapia to produce sterile offspring.

A UN science panel warned in 2023 that tilapia fish are spreading faster than ever, wrecking crops, distributing disease and upending ecosystems.

More than 37,000 alien species have taken hold far from their places of origin, costing upwards of US$400 billion (S$523 billion) a year in damage and lost income, the UN panel said. AFP