African Catfish Turn Predators In Bangladesh

July 14, 2004

Release from: Sharier Khan
OneWorld South Asia

DHAKA - Apart from increasingly saline water and over fishing, Bangladesh's river life is now under threat from a carnivorous alien species called the African catfish that is rapidly multiplying and attacks both humans and other water beings.

Ironically, officials of the Fisheries Department brought the African catfish to Bangladeshi waters. It was one of 14 fish varieties introduced by authorities since 1953.

While the impact of other alien fish species seems to have been negligible, the African catfish noticeably wiped out indigenous fish populations in ponds and water bodies they lived in. Another predator species is the Telapia fish.

In a shocking incident last year, African catfish killed the three-year old son of a farmer in Mymensingh, 120 kilometers from Dhaka, when the toddler was playing in the shallow waters of a pond.

Some fish farmers complain African catfish are harmful to cultivate because they destroy all other species living with them.

Says Shamim Ahmed, a fish farmer in Narayanganj town on the outskirts of Dhaka, "(When officials introduced these fish), they thought it would revolutionize the fisheries sector in the same way broilers revolutionized the poultry sector. But they are harmful for local fisheries and consumers avoid purchasing them because of their carnivorous reputation and ugly appearance."

Ahmed complains that when he introduced African catfish into a cultivation pond three years ago, they devoured all the other fish species in the pond. He had to poison the pond waters to kill all the fish and re-start cultivation.

Bangladesh occupies the fourth spot in the world in aquaculture production, with the fisheries sector contributing 5.9 percent to the Gross Domestic Product (GDP). But due to the high population density, the annual per capita fish consumption is about 13.5 kilograms, against a minimum requirement of 18 kilograms.

The World Conservation Union (IUCN) put 54 fresh water fish species in Bangladesh on the endangered species list in 2001.

Environmentalists say over-fishing is the main reason for this situation, followed by environmental degradation and the unplanned installation of structures in the upstream river.

"Even the use of chemical fertilizers is a cause of concern," says Ainun Nishat, the country representative of IUCN.

In Bangladesh, two million tons of chemical fertilizer and 7,000 tons of pesticides are being used. Solid wastes are also a threat to fishes. Dhaka city alone generates 5,000 tons of solid waste containing lots of toxic material that flows unchecked into sources of drinking water.

Many of these problems arise from uncontrollable national factors like population growth and overcrowding. "But the cultivation of African catfish is something we could well have avoided," says environmental activist Khasru Chowdhury.

Strangely, the government has not yet banned the cultivation of this species, which is also known to be quite resilient.

Last month, sewer cleaners caught a 20-kilogram African catfish from Dhaka's storm sewage system. In contrast, the biggest local catfish would not weigh more than two kilograms.

"It was a huge monster," recalls Sohel, a 20 year-old-cleaner who was part of the group that cornered the catfish with rods, machetes and other weapons. "When we got down the sewer, we saw something huge moving around in the murky sludge. When we tried to catch it, it attacked us. It took more than an hour to track it and kill it," Sohel reveals.

Sewer cleaners claim there are more African catfishes in the sewers.

Agrees Shakhawat Hossain, a resident of Kathalbagan in Bangladesh's capital Dhaka. "Last year I saw two men catching African catfish from the sewage line," says Hossain.

Warns Ainun Nishat, "As Bangladesh is a flood prone country, the government should have taken a clear cut policy before introducing such carnivorous species. If this catfish spreads in our rivers or wetlands it will eat up all the other fish species."

While people do not consciously eat African catfish, this undesired species is widely being cultivated in suburban areas to cater the high demand in the city's cheaper restaurants. African catfish supplied to these restaurants are not fully-grown -- so that they resemble a large sized indigenous catfish that consumers love to eat.

"Restaurants buy the fish at very cheap rates and sell them at higher rates to unsuspecting customers who believe they have eaten large-sized indigenous catfishes at unbelievably low prices," admits Shahjahan, an African catfish grower.

Indigenous catfish costs three to four times more than African catfish.

In the low-lying outskirts of Dhaka, African catfish are being cultivated in specially constructed tubs or submerged bamboo cages in ponds. According to cultivators, they supply up to 3,500 kilos of catfish to the capital and its suburbs from 200 such farms.

Says Abdur Razzak, the caretaker of one of the biggest African catfish cultivators, Kalam Mia's firm, "They multiply fast, are possible to cultivate even in the most contaminated water and will feed on whatever you give them."

In revelations that could make fish lovers' stomachs squirm, Razzak adds, "They are always hungry and we feed them anything -- from rotten leftovers of cattle from the butchers' shops to the garbage of restaurants."

Hundred kilos of catfish can transform into 400-600 kilos within just two months.

Cultivator Haider Mia explains the economic benefits. "In terms of investment, I spend about $250 dollars for the catfish for two months and get returns of $415."

Says Fisheries Secretary Iqbal Uddin Ahmed Chowdhury, "The government has stopped encouraging the cultivation of such species as they are harmful for the ecosystem. We believe they will diminish from the ecosystem naturally someday."

But he admits the government does not plan to prohibit the cultivation of African catfish.