BANGKOK: The Department of Fisheries has announced that local predatory fish species can be used to effectively hunt and eliminate the invasive blackchin tilapia.
Research has also confirmed that this method does not harm the environment or the ecosystem in the long run, as it is biologically sound.
Bancha Sukkaew, the department’s director-general, said on Friday that the spread of the African fish species has significantly impacted fishermen and the aquatic ecosystems across 16 provinces. In response, Agriculture and Cooperatives Minister Thamanat Prompow ordered urgent measures to address this issue.
To tackle this problem, the department has come up with several measures. One involves continuously releasing local predatory fish species as well as capturing larger blackchin tilapia. Once the number of large blackchin tilapia is reduced, the released predatory fish will target smaller tilapia and thus control their reproductive cycle.
The other measure is educating the public about the use of predatory fish. This method, widely studied and used in many countries, employs releasing predatory fish in areas where fishing is impractical, such as mangroves or obstructed water bodies. This approach effectively addresses the spread of invasive species without long-term environmental or ecological impact.
In an initial study, the department used Asian seabass and long-whiskered catfish in a natural simulation environment and found that these predatory fish can instinctively hunt and consume up to 12 blackchin tilapia fry measuring about 3 centimetres daily.
However, they can only consume larger tilapia once they are fully grown, and the tilapia pose them no danger because they have smaller jaws.
“Other predatory species like clown knifefish, snakehead fish and can also help control blackchin tilapia. Choosing a suitable predatory species and release rates based on the characteristics and ecosystems of each water body are crucial to maintaining ecological balance and avoiding negative impacts on native aquatic species. This also ensures the survival of the predators,” Bancha said.
Fisheries offices in provinces facing the problem of blackchin tilapia invasion will offer proposals to the provincial blackchin tilapia control committee, which will then submit them to the department for approval.
The department is confident that the continuous release of predatory fish will effectively control blackchin tilapia populations. Pilot releases have already begun in some areas such as Samut Sakhon and Rayong.
“The department will continuously monitor and evaluate the effectiveness of predatory fish releases in controlling the reproduction of small blackchin tilapia populations. As the control of blackchin tilapia improves and their numbers decrease, the department will promptly release native aquatic species to restore the richness of Thailand’s aquatic resources,” Bancha said. - The Nation/ANN
