Roughly 25 percent of the freshwater fish species in Bangladesh are at risk of extinction due to adverse climate change impacts, shrinking habitat, overfishing and widespread use of pesticides and fertilisers in agriculture.
Sixty-four species, or one-fourth of the total evaluated freshwater fishes of 253, are threatened, according to the ‘Red List of Threatened Species’ maintained by the International Union for Conservation of Nature (IUCN).
Among the 64 species, nine [or around 3 percent of Bangladesh’s total fish species] are critically endangered, 30 [or 12 percent] are endangered and 25 [or 10 percent] are vulnerable.
Of the rest of the species, 25 [or 11 percent of the total fishes] are nearly threatened and 122 [or 48 percent] are safe while sufficient data could not be found about another 40 [or 16 percent] fish species.
Dr Mostofa Ali Reza Hossain, professor of Department of Fisheries Biology and Genetics at Bangladesh Agriculture University, told daily sun that some of the threatened fish species have already become extinct.
He blamed overfishing, destruction of water bodies, adverse climate change impacts, use of pesticides and fertilisers, industrial pollution, alien fish farming and use of illegal aquaculture drugs for the decline in the number of fish species in the country.
He said the assessors of IUCN could not find any information about 40 fish species. “So we can assume that those fish species have died out from the country,” he added.
“There are 57 transboundary rivers in Bangladesh of which 54 are connected with India and three with Myanmar,” he said, adding that fish species in those 57 rivers are being extinct due to random misuse of rivers on the upper stream.
He said 70,000-80,000 tonnes of pesticides are being used in farmlands in Bangladesh of which nearly 12,000 tonnes are drained to water bodies each year, making the small fish species, fry and eggs of different local fishes more vulnerable.
Professor Hossain also said unnecessary breeding of foreign fishes is also posing threat to local fishes.Around 25 alien fishes are now being farmed in Bangladesh.
“The overall fish production is increasing in Bangladesh, but the production of freshwater fishes is decreasing,” he said.
Country’s overall fish production stood at 3.68 million tonnes in FY 14-15 from 3.54 million tonnes in FY 2013-14.
Of the total fish production, 27.79 percent is captured from inland open water sources, 55.93 percent produced in closed water and 16.78 percent came from marine water in FY14-15, according to a report of the Food and Agriculture Organization (FAO).