- Citizens rallied in Bangkok this week demanding accountability and action from the government and private corporations following an outbreak of invasive fish that has ravaged Thailand’s freshwater ecosystems and aquaculture industry.
- Blackchin tilapia, an omnivorous species native to West Africa, is highly adaptable, breeds rapidly and is capable of outcompeting native wildlife and commercially farmed species, including shrimp.
- Thailand’s largest agricultural conglomerate has come under scrutiny because it obtained a permit to import the species in 2010, shortly before the first detections in the wild in the same province as its research facility.
- The activists urged the government to eradicate the species, compensate affected farmers and identity the parties responsible for the outbreak.
BANGKOK — Farmers and environmental advocates rallied in Bangkok Jan. 13 to demand the government and a private corporation take serious action to address the escalating spread of blackchin tilapia, a highly invasive species of fish, in Thailand’s waterways.
Fisheries department surveys have identified blackchin tilapia (Sarotherodon melanotheron) in 19 provinces surrounding the Gulf of Thailand, encompassing Bangkok, south to Songkhla province and east to Chanthaburi, stoking fears the species could make its way into neighboring Cambodia. Shoals of the species are overgrazing algae and planktivorous animals that form the basis of the aquatic food chain, depleting freshwater ecosystems and impacting shrimp and other aquaculture businesses.
Academics say the invasion is a “critical ecological threat,” and while fishery officials pulled some 1,300 metric tons of blackchin tilapia from affected waterways between February and August 2024, the activists say they’re disappointed with the way authorities have handled the crisis.
“The government and various agencies have not taken consistent and serious action,” Thira Wongcharoen, a farmer from Chanthaburi province, said at the rally.
Roughly 150 demonstrators from the 19 affected provinces, including fishers, small-scale aquaculture farmers and academics, attended the rallies in Bangkok outside Government House and in front of CP Tower, headquarters of CP Group, which they blame for introducing the fish into the country.
The species is native to brackish coastal habitats in West Africa and has a physiology that makes it a formidable invasive. Blackchin tilapia breed rapidly year-round, survive in both freshwater and saltwater, and have an omnivorous diet, preying on native species of fish, shellfish and other invertebrates.
Experts have likened the species to a “perfect storm” given its resilience, adaptability and capacity to outcompete both native and commercially farmed species. “Furthermore, this species does not taste as good as other species, such as Nile tilapia, Mozambique tilapia, or gourami, making it unpopular among fishermen as well,” Thotsapol Chaianunporn, an environmental scientist at Khon Kaen University, told Mongabay.
From both a nutritional and economic standpoint, the threats are significant. Fish products comprise 19-35% of people’s daily intake of protein in Thailand. And as declining wild fish populations have impacted wild capture fisheries, the aquaculture industry now accounts for more than half of national fisheries economic production, which in turn contributes 1.5% of the country’s annual GDP, according to the Southeast Asian Fisheries Development Center.
Disputed origins
Fishers began noticing the troublesome species in waterways in Samut Songkhram province in 2012, according to local media reports. While the origins of the invasion are mired in controversy and legal exchanges, Samut Songkhram is home to the only aquaculture facility in Thailand that has ever obtained a permit from the Department of Fisheries to import the species.
The facility is operated by Charoen Pokphand (CP) Foods, a subsidiary of Thailand’s largest agricultural conglomerate, CP Group. It imported 2,000 blackchin tilapia from Ghana in 2010 for research purposes. Although CP Foods claims it destroyed all of the imported fish after its experiment failed, the company has been at the center of a legal battle with activists since September 2024 about whether it played a role in the outbreak.
CP Foods is a major player in Thailand’s livestock and aquaculture industry and dominates the feed sector. As such, the corporation wields significant influence over Thailand’s natural resources, being cited as one of the world’s most influential corporations in terms of global fisheries. The company didn’t respond to requests for comments for this story.
Carrying signs, fishing nets and blackchin tilapia caught in Bangkok, the activists delivered letters to CP Foods, the prime minister’s office and three parliamentary committees that have been established to address the outbreak.
They called on the government to establish a clear plan to eradicate the species by 2026 and to declare outbreak hotspots as disaster zones to release emergency funds for compensating affected farmers. They also urged authorities to swiftly identify the parties responsible for the outbreak and hold them legally accountable for the costs of the damage in accordance with the “polluter pays” principle. Via the letter to CP Foods, the group demanded the company accept responsibility for the outbreak and make due amends.
Aquaculture farmers claim to have lost access to natural resources and vital income from businesses decimated by the spread of the invasive fish. A study by Thammasat University researchers found that just one subdistrict of Samut Songkhram province sustained economic losses amounting to roughly 132 million baht ($3.8 million) due to the impact of the invasion in 2020. Experts have estimated the outbreak as a whole could cost the country at least 10 billion baht ($293 million).
“The blackchin tilapia destroy everything in the ecosystem,” Wanlop Kunjeng, a former shrimp farmer from Samut Songkhram province, told Mongabay. After his shrimp ponds were decimated by blackchin tilapia roughly 10 years ago, Wanlop said he had to switch to farming a type of seabass instead.
The unexpected transition has been financially tough, according to Wanlop. Stocking his ponds with fish large enough to withstand the onslaught of the blackchin tilapia incurs significantly higher up-front costs, he said, compared to his shrimp-farming days. Moreover, the time it takes to see a return on his investment is roughly six months longer than for shrimp. The hardships he and his fellow farmers have had to endure must be compensated, he said.
Once established, ‘impossible’ to control
The invasion has also raised concern among conservationists about the risks of introducing invasive nonnative species into local ecosystems. “Thailand’s rivers, including the Mekong, Chao Praya, and Mae Klong, are home to a plethora of rich and diverse habitats,” Kathy Hughes, freshwater biodiversity lead at WWF Greater Mekong, told Mongabay in an email. “Consequently, Thailand’s fishes are equally diverse, and many of them are found nowhere else on earth.”
Hughes said that once invasive species get into the wild, they’re notoriously hard to control. There should be strict regulations to control imports of nonnative species, and those who ignore the regulations should be held accountable, she added. “Non-native species should not be introduced in the first place.”
Scientists often cite that the window of opportunity to effectively manage invasive species is very tight. Multiple sources told Mongabay that this time frame has already passed for blackchin tilapia in Thailand. “There is no hope of eradicating them from our waterways now,” said Nonn Panitvong, a freshwater ecosystem specialist and founder of citizen science website Siamensis.org. “We will have to learn to live with them.” Nonn said the best way to give native species a “fighting chance” is ensuring waterways and the fish that live in them are in the best possible condition.
While it may well be a losing battle, the government announced funds to develop and implement control measures in July 2024. These include the release of native predators like Asian seabass (Lates calcarifer) and long-whiskered catfish; trialing the release of blackchin tilapia genetically modified to produce infertile offspring; and incentivizing people to catch blackchin tilapia through a buyback scheme at rates significantly higher than market prices.
A 2024 study that evaluated potential management of the species in Thailand concluded that capturing and finding ways to utilize blackchin tilapia is likely to be the most effective measure. Releasing predators that didn’t co-evolve with the African species might have limitations, the authors said, given large fish may instead feed on other native fish or zooplankton species.
The study’s lead author, Thotsapol Chaianunporn, said the government response to the outbreak was ultimately too slow. “The response of the government was very slow as all controlling measures were implemented 13 years after the first report of blackchin tilapia in natural waterways,” he said. “Had the government acted more swiftly, it might have been possible to eradicate or contain the affected water bodies.”
Thotsapol recommended that instead of importing species from overseas for aquaculture research, Thailand should focus its research and investment on native species, thereby mitigating the risks of harmful invasions. He and his colleagues also say in the study that ongoing monitoring to track the spread of fish through waterways is vital, and could be assisted by the creation of an online platform.
Legal exchanges
The protests follow a series of legal exchanges over the matter. In September 2024, the Lawyers Council of Thailand filed a lawsuit against the government on behalf of a group of 1,400 farmers from Samut Songkhram province, accusing authorities of failing to remedy the situation in a timely manner. The farmers’ group also mounted a legal challenge against CP Foods, demanding compensation for livelihood losses due to the invasion.
Although CP Foods initially denied responsibility for the outbreak and committed its support to government-led eradication efforts, it subsequently raised a defamation lawsuit against the secretary-general of the BIOTHAI Foundation, a Thailand-based food sovereignty NGO, alleging the group had released “misinformation” about the company’s involvement.
The firm has been slammed for pursuing such legal channels rather than engaging in proactive dialogue with affected parties. “Lawsuits, like the one CP has filed against BIOTHAI, are used by companies to obstruct people from holding them to account,” Angus Lam, Asia lead for GRAIN, a nonprofit supporting small farmers, told Mongabay in an email. “But, as seen from yesterday’s rally, communities are not being hushed, more farmers and fisherfolks have come out to demand justice.”
According to Lam, the outbreak of blackchin tilapia has essentially increased CP Foods’ control of an industry it already dominates. “The species has destroyed traditional systems of shrimp cultivation along the coastlines that do not require commercial feeds and has forced small-scale fish farmers to use intensive, closed systems that rely on feeds, chemicals, and antibiotics supplied by agribusiness.”
Banner image: Activists carry signs along the streets of Bangkok calling on the government and private corporations to take action and accept responsibility. Image by Carolyn Cowan/Mongabay.
Carolyn Cowan is a staff writer for Mongabay.
Citations:
Chaianunporn, T., Panthum, T., Singchat, W., Chaianunporn, K., Suksavate, W., Chaiyes, A., … Srikulnath, K. (2024). Sustainable ecosystem management strategies for tackling the invasion of blackchin tilapia (Sarotherodon melanotheron) in Thailand: Guidelines and considerations. Animals, 14(22), 3292. doi:10.3390/ani14223292
Sampantamit, T., Ho, L., Lachat, C., Hanley-Cook, G., & Goethals, P. (2021). The contribution of Thai fisheries to sustainable seafood consumption: National trends and future projections. Foods, 10(4), 880. doi:10.3390/foods10040880
See related story:
FEEDBACK: Use this form to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.
