Civil society groups are demanding the government immediately find out who is responsible for the spread of blackchin tilapia, an invasive species of fish that has caused havoc with local species.
That the fish have been allowed to spread shows that the government failed to take legal action against the wrongdoers, Withoon Lienchamroon, director of the BioThai Foundation, said on Friday. He made the remarks during a seminar titled "Natural disaster from blackchin tilapia" organised by the foundation and its allies.
Mr Withoon said that in 2010, Charoen Pokphand Foods (CPF) imported 2,000 blackchin tilapia from Ghana for research and development purposes at its breeding centre in tambon Yisan of Amphawa district in Samut Songkhram province.
The company claimed that all of the imported fish had died within three weeks of arriving in Thailand, yet people reported finding them two years later in Khlong Don Chan, Khlong Luang and Khlong Somboon near the company's breeding centre, he said.
Today, the fish has spread to 17 provinces from the Central region to the South.
CPF was the only company allowed to import the fish by the Department of Fisheries.
Meanwhile, a study on the "Origin and Distribution of Invasive Blackchin Tilapia on Coastal Area of Thailand" by the same department showed a genetic link between the more recently found fish came from the same source, Mr Withoon said.
"It's obvious who should take responsibility. But we have not seen the right action from the company," he said.
"The government has been spending taxpayers' money to deal with this problem, which isn't fair on us. We need to see the law enforced on the perpetrator."
Surachai Trongngam, EnLaw's secretary-general, suggested the department defer to the Enhancement and Conservation of National Environmental Quality Act BE 2535.
Section 97 states the polluter must take responsibility for any environmental damage caused by their actions. The department may face a malfeasance charge.
The department estimates that in 2018, the alien species caused losses of 350 million baht to aquatic farms in Samut Songkram and Phetchaburi.
The Lawyers Council of Thailand will file a complaint against CPF and the department.