In June 2023, the Fisheries Department of Krishnagiri, Tamil Nadu, issued a stern warning against individuals involved in breeding African Catfish—also known as Thai Magur—reiterating the species’ prohibited status in India. This is not the first instance of the fisheries department issuing such a ban related to this species of fish. Despite the ban, originally outlined in a 1997 government directive from the Department of Animal Husbandry, Dairying and Fisheries (DAHD&F), the Ministry of Agriculture, the farming and sale of African Catfish continue in the open market.
In 2000, the Ministry of Agriculture, Department of Animal Husbandry and Dairying (Fisheries Division) invoked the Environment Protection Act to ban the African catfish due to its adverse environmental impact. Furthermore, the National Green Tribunal enforced a prohibition on the rearing of this species through order no. 435/2018 dated 22 January 2019, citing its significant threat to numerous local fish varieties and its contribution to water pollution. Originally introduced globally for aquaculture in 1980, this fish found its way into India without official authorisation. It is noteworthy for its ability to endure extended periods in shallow mud and its high tolerance for poorly oxygenated water. The warning emphasises that breeding this prohibited fish is a violation of the law, and appropriate legal action will be taken against offenders.
While the African Catfish—or Clarias gariepinus—is known for its nutritional value, offering a wealth of nutrients, it simultaneously poses a serious risk to the aquatic ecosystem. This member of the Clariidae family covertly entered Indian states around 1994, subsequently spreading throughout the country, including temperate and coastal regions, with significant cultures established in West Bengal and Andhra Pradesh. Its presence in India resulted from an unauthorised introduction following its global distribution for aquaculture in the 1980s. The catfish’s invasive nature is marked by its adaptability and predatory habits. It preys on live and dead animals, fish, and other invertebrates, and occasionally even targets small birds. Capable of thriving in minimally oxygenated and shallow waters, this species outcompetes and endangers native fish populations due to its rapid growth rate.
Additionally, a close relative—Clarias batrachus, also part of the Clariidae family—is recognised as a freshwater species. A hybrid version, known as Hybrid Mangur (C. gariepinus x C. macrocephalus), is bred in Bangladesh and illicitly trafficked into Indian states such as Assam, West Bengal, and Bihar, fueling an illegal but profitable trade. This hybrid variety is favoured for its rapid growth and cost-effective feed made from recycled chicken and slaughterhouse by-products, with West Bengal serving as the epicentre of African Catfish seed production.
For farmers, the African Catfish presents an enticing economic opportunity, as a modest investment can yield significant returns. However, the species poses a considerable ecological threat, with the potential to decimate indigenous fish species and disrupt the delicate ecological balance. Although catfish are sometimes recommended by doctors for their medicinal properties and can meet daily nutritional needs with their high protein, iron, and low-fat content, the environmental consequences of their cultivation are too significant to overlook.
The African Catfish can have detrimental effects on aquatic ecosystems, and these impacts become evident through various scenarios. In one instance, the catfish’s predatory nature comes to the forefront as it preys on native species, such as local perch or sunfish, leading to declines in these populations. The competitive advantage of African Catfish becomes apparent in another scenario, where they out-compete native species for vital resources like food and habitat. For example, in a pond, the introduction of African catfish may result in reduced availability of insects and aquatic plants, resources that native species depend on for sustenance and shelter. Moreover, the habitat alteration caused by the catfish is observable in wetlands and marshy areas. Their burrowing behavior and tolerance for shallow, muddy waters can disrupt the natural structure of the habitat, impacting the breeding and sheltering grounds of native amphibians and fish species.
The African catfish is highly regarded by fish farmers for several practical reasons. This species requires minimal maintenance, which is economically advantageous for aquaculture operations. It is remarkably resilient, able to thrive in less than ideal water conditions, including those with low oxygen levels or higher levels of pollution. One of the unique aspects of African catfish farming is their ability to grow on a diet that includes poultry waste, making their feeding regime not only cost-effective but also an efficient way to recycle agricultural by-products. Their rapid growth rate is particularly beneficial; African Catfish can reach a substantial size of 3-4 kilograms within a month, allowing farmers to cycle their stock quickly and get products to market at a faster rate. This quick turnaround, coupled with their low production costs, means that catfish can be sold at competitive prices, providing a cheap source of protein to consumers and making the fish a lucrative commodity for farmers.
These attributes make the African Catfish an attractive option for fish farming, especially in regions seeking affordable and sustainable ways to increase food production. However, the ecological concerns associated with farming non-native species, such as the potential for them to escape and disrupt local ecosystems, must be managed carefully to prevent environmental impacts.
Regarding the nutritional benefits of African catfish, many are unaware that this fish is not good for human health, as numerous scientific studies have indicated that consuming it is associated with an increased risk of developing cancer. Due to its carcinogenic properties, medical professionals advise against consuming this fish. Furthermore, the Thai Magur can harbour disease-causing parasites, such as fish lice (Argulosis), which can potentially lead to harmful outbreaks in aquaculture operations, causing adverse effects.
Even after the ban on African catfish in India, illegal cultivation continues, and this fish can still be found in the market. One of the reasons for this is that the public is not fully aware of the ban on African Catfish and its harmful effects on the human body. Awareness needs to be raised among both the general public and fish farmers. Despite its affordability, this fish has the potential to harm our aquatic ecosystems and our health.
Dr. Piyali Chatterjee is the Head of Department for the Faculty of Law, ICFAI University, Raipur Chhattisgarh