Tilapia Invasion Devours Farmed Fish and Shrimp as Fishers Seek Compensation from CP Group
On 4 February, Thailand’s Department of Fisheries announced that they had just successfully bred a genetically modified Blackchin tilapia. The offspring produced when this modified tetraploid tilapia is mated with a natural diploid tilapia cannot reproduce, and the government hopes this will help reduce the numbers of this African invasive species and reverse the damage to the ecosystem.
At present, Blackchin tilapia are proliferating in up to 19 provinces across Thailand, destroying local aquatic ecosystems. Environmental scientists have therefore stated that the spread of Blackchin tilapia is “the most severe ecological destruction in Thailand’s history”.
This news prompted concern among the public and the scientific community: what impact might chromosomally modified experimental animals released into the natural environment have on ecosystems and related species? A more cautious approach is warranted.
The Thai government’s move has more than a touch of “fighting magic with magic” about it: the attempt to invade the natural environment with modified, artificially sterilised tilapia in order to defeat a naturally occurring invasive species. It is worth remembering that the very reason Blackchin tilapia first spread from Africa to Thailand was also a failed experiment.
According to Thai media reports, CP Group subsidiary CP Foods imported 2,000 Blackchin tilapia from Ghana in 2010 for breeding trials at its fish farm in Amphawa District, Samut Songkhram Province. This was, on record, the only occasion on which the species was ever introduced into Thailand. At the time, CP Foods’ import experiment was primarily intended to improve the disease resistance of commercially farmed Nile tilapia and to test Blackchin tilapia’s adaptability to saline water, meeting its ever-expanding industrial farming needs.
Despite CP Foods insisting that the experiment was unsuccessful and that the project was swiftly terminated, people began finding Blackchin tilapia around the experimental fish farm. Before long, traces of the species appeared in rivers across multiple Thai provinces and even in Bangkok’s canals.
On 13 January 2025, more than 200 representatives from 19 Thai provinces gathered outside the CP Group building in Bangkok. Acting on behalf of fisherfolk devastated by the Blackchin tilapia invasion, they denounced CP Group and its subsidiary CP Foods. Speaking to the media, they stated that over the past decade and more, the Blackchin tilapia invasion had caused the collapse of local ecosystems and threatened fishers’ livelihoods. They demanded that the government take action and that CP Group pay compensation.
I. Tilapia Invasion
Its extraordinary adaptability and reproductive capacity mean that, once it enters a non-native natural environment, it can instantly become an invasive species that devastates the local ecosystem. In southern China, tilapia is currently the most dominant invasive fish species. Two close relatives of the Blackchin tilapia – Nile tilapia and Zille’s tilapia – were introduced into China in 1978 and promptly found their way into the country’s natural waterways. Research shows that in certain stretches of the Pearl River Basin, tilapia stocks even exceed the combined total of all other fish species.
A similar scenario has unfolded in Thailand. A statement submitted by demonstrators to Thailand’s Prime Minister reads: “Blackchin tilapia have consumed every last scrap of food in ponds and natural canals; they feed on plankton and juvenile aquatic animals. As a result, shrimp, fish, molluscs, and crabs in ponds – along with other aquatic species in natural water sources – have been devastated.”
When natural ecosystems are damaged, it is individual fishers engaged in traditional fishing and aquaculture who bear the brunt first.
The independent outlet Mongabay quoted Wanlop Kunjeng, a former shrimp farmer in Samut Songkhram Province, who said that ten years ago his shrimp ponds were destroyed by Blackchin tilapia, forcing him to switch to farming seabass – a species large enough to withstand the tilapia’s attacks. But the trade-off was higher upfront costs than shrimp farming, along with a far longer payback period.
Lin Zhiguang, Southeast Asia lead for GRAIN, an organisation that has long supported small-scale farmers, told Mongabay that Blackchin tilapia “have destroyed traditional coastal shrimp-farming systems that require no commercial feed, forcing small-scale farmers into intensive, closed systems that depend on feed, chemicals, and antibiotics supplied by agribusinesses”.
And unlike other commercially farmed tilapia species, Mongabay also quoted an environmental scientist at Khon Kaen University, noting that the flesh of Blackchin tilapia does not taste as good as that of other commercial tilapia species, so even when fishers catch them, there is little local demand.
According to data from the Lawyers Council under Royal Patronage, direct economic losses suffered by fishers amount to 2.486 billion baht (approximately RMB 533 million), while additional losses to society and ecosystems exceed hundreds of billions of baht – yet even these estimates are considered too low. “Many people are heavily in debt or have lost their land, and some have even taken their own lives, particularly in Samut Songkhram Province.”
In July 2024, the Thai government added controlling the Blackchin tilapia outbreak to the national agenda, approving a budget of 450 million baht (approximately RMB 97 million) to encourage harvesting of the species at up to 15 baht per kilogram (approximately RMB 3).
But the government buyback scheme lasted less than four months, and in its latter stages the purchase price dropped to 3–4 baht per kilogram (approximately RMB 0.6–0.8). At that rate, fishers would have to catch one tonne a day just to turn a profit – an arduous task. Many simply stopped fishing once the government ceased buying.
II. What Responsibility Does CP Group Bear?
In 2017, affected community fishers and farmers filed a petition with the National Human Rights Commission of Thailand, seeking redress and government intervention.
CP Foods, for its part, denies any responsibility for the environmental crisis. The company claims that it did indeed import Blackchin tilapia from Ghana in December 2010 for research purposes, but that a month later the fish grew weak and died, and the project was abandoned. The company then disposed of all the fish using approved methods and sent samples and documentation to the Department of Fisheries.
However, the committee that heard the petition reported that CP Foods had failed to comply with the biosecurity regulations set by the Department of Fisheries. It noted: “The company failed to report Blackchin tilapia test results and mortality in writing, which violated the standards and conditions of the non-indigenous aquatic species licence.”
Since then, despite multiple investigations by the Thai government, the origin of the Blackchin tilapia outbreak has still not been officially attributed, leaving affected fishers unable to seek accountability and claim compensation from CP Foods.
In July 2024, the BioThai Foundation, a Thai non-profit organisation focused on biodiversity and sustainable agriculture, announced it would pursue corporate accountability through legal means. Withoon Lienchamroon, a board member of the foundation, told the Bangkok Post: “The government has been spending taxpayers’ money to fix this problem, which is unfair to us. We need the perpetrators to face the full force of the law.”
The rally on 13 January this year reiterated the demand for compensation through litigation and called on the government to identify the party responsible for the ecological disaster. The open letter issued at the rally noted that CP Foods’ profit for the third quarter of 2024 alone reached 7.3 billion baht (approximately RMB 1.56 billion). They argued that CP Group, “as a publicly listed company, should redistribute a portion of its profits to society to address issues such as the Blackchin tilapia outbreak”.
III. Will There Be a Response?
Even if everything proceeds smoothly, the process of ecological restoration will be far more difficult and drawn-out than pursuing accountability and compensation, and Blackchin tilapia itself will not be “eradicated” as people hope. A Thai fisheries expert told the BBC: “The problem with invasive species is that, once they have settled in, they are extremely difficult to eliminate.”
Thailand’s independent media outlet HaRDstories quoted a senior aquatic ecologist from the Mekong River Commission warning that without action to address the problem systemically, within the next five years the Mekong Delta and Singapore may also come under threat.
It is easy to foresee that this protracted struggle – between people and people, between people and nature – over the Blackchin tilapia is far from over.
In its solidarity statement, MASIPAG wrote that it is “corporate greed and indifference to ecological and community welfare that have fuelled this environmental catastrophe.” A small number of invasive organisms can produce such far-reaching and irreversible impact – can those who remain short-sighted take heed? Without mechanisms to hold perpetrators to account, compensate losses, and restore the environment, and without careful regulation of breeding experiments like this one, environmental disasters born of economic interest will remain inevitable for years to come.
❸ The Cabinet must establish a national-level committee and province-level working groups to eradicate Blackchin tilapia, restore ecosystems, and revive the livelihoods of farmers and others affected. The committee and working groups must set a target of completely eradicating Blackchin tilapia by 2026 and allocate the necessary budget.
❹ Once the investigation is complete and responsibility has been established, the government must file legal charges and pursue litigation proceedings against the responsible party. The party at fault must compensate losses and pay for damages, so that the cost of restoration does not fall on Thailand’s taxpayers.
References
https://www.bangkokpost.com/thailand/general/2941950/invasive-blackchin-tilapia-spreading-again-in-thailand
https://www.bangkokpost.com/thailand/general/2836047/cp-foods-no-show-at-panel-meet-on-alien-fish
https://bkktribune.com/cpf-accused-of-breeding-blackchin-fish-since-first-fish-import/
https://bkktribune.com/series-of-legal-action-taken-in-blackchin-tilapia-fish-invasion-case/
Editor: Wang Hao