Indigenous fish species disappearing: Experts

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UNB, Dhaka :
The indigenous fish species, particularly the small ones, are facing extinction on the basin of the Old Brahmaputra River due to rapid habitat loss, water scarcity, overfishing, unchecked use of agro chemicals and climate change, according to experts.
They said, the local fish varieties that are facing extinction are mola, dhela, koi, napit koi, kajoli, baspata, chital, chanda, sarputhi, jat puthi, tit puthi, meni, bele, baim, taki, foli, boal, rani, chela, darkina, pathorchata, khalisha, lal khalisha, tara biam, bata, gutum and tengra.
The freshwater fishes in Bangladesh are comprised of 265 species and about 140 of them are the small indigenous ones, according to data of Wildfish Centre in Dhaka.
“Habitat destruction is a major reason behind the rapid loss of native fish species. Agro chemicals are destroying the breeding grounds of the fishes endangering their existence,” Prof Dr Mahmud Hasan, a teacher of Dhaka University’s Fisheries Department, told UNB.
Framers indiscriminately use agro chemicals and pesticides to boost their crop production and prevent pest attacks. After rains, the agricultural runoff containing pesticides and other chemicals come down to the water bodies, destroying the natural habitats of fish, he said.
Prof Mahmud said, the pesticides used in agricultural land fall into water bodies and destroy zooplankton. “As the native fish species, particularly the small ones, can’t take food for lack of zooplankton, they can’t properly grow and breed,” he added.
As there is no law to regulate the use of pesticides, farmers are using those in agriculture whimsically and thus are destroying the breeding
grounds of fishes, said Prof Abdul Quader, a retired teacher of the Marine Science and Fisheries Institute at Chittagong University.
According to the experts, the breeding grounds of the fish have been drastically reduced due to inadequate rainfall apart from siltation in rivers, water-bodies and floodplains.
“There’s no enough water in the country’s water bodies and rivers due to scanty of rainfall which affects the country’s fisheries sector,” Dr Manzarul Karim, a scientist of the Worldfish Center, told UNB.
Referring to erratic rainfall caused by climate change, he said many rivers and wetlands of the country are dying day by day due to insufficient rainfall, endangering the indigenous fishes further.
As a lower-riparian country, he said, Bangladesh is also facing scarcity of water because of withdrawal of that from the common rivers by the upstream countries.
Dr Karim said, climate change will pose a serious threat to aquaculture in the country’s coastal region, particularly in the Sundarbans, as the sea level will keep on rising due to global warming in the future affecting the coastal freshwater ecosystem.
Identifying overfishing as the key reason behind the fast disappearing of small varieties of local fish, Prof Abdul Quader said, people are aggressively catching fishes from rivers and water bodies to meet their food demand without considering about the future.
“During the dry season, local people catch all varieties of fish from water bodies withdrawing water from them. They indiscriminately catch all mother fishes,” he said.
Quader said the indigenous fish varieties are also disappearing fast since the water bodies, including rivers, haors, canals and wetlands are being grabbed by influential people.
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