At least 28 species of indigenous fish have gone extinct and five out of 650 bird species in the country have disappeared in the recent past due to environment pollution and human encroachment.
The department of fisheries also identified 28 extinct species of indigenous fish. Of the remaining 260 fish varieties, 10 per cent are now considered either critically endangered or vulnerable. The drying of and silting in rivers, ponds and wetlands, indiscriminate use of pesticides and insecticides on agricultural land, and a spate of construction work throughout the country have contributed to the decline in fish varieties, said Prof. Dr Mohammad Anwarul Islam of the department of zoology, Dhaka University.
He cited the fate of frogs, especially bull frogs (“kola bang”), whose mating calls heralded the arrival of the monsoon.
Now their sounds are a rarity. Export of these harmless aquatic creatures, despite the ban on it, has dealt a crippling blow to their population. The presence of frogs is indicative of the survival of other aquatic lives, said Prof. Islam, a leading conservationist of the country.
Experts fear the rate of extinction of frogs will accelerate in the years to come, especially because of loss of habitat.
It is against this backdrop that the nation is observing “Water and Biodiversity Day” today to remind people of the need for conservation of nature.
The primates in different pockets of Madaripur, and the langurs and other big apes desperately clinging to the surviving trees in the Keshabpur forest of Jessore, Rema Kalinga and Sapchhari forests in Maulvibazar and Habiganj tell a sad story of their own.
Abdus Sobhan, former additional director general of the department of environment, said industrial pollution, encroachment, deforestation, dumping of burnt oil residues and effluents from water vessels and sewers, excessive use of pesticides and fertilisers were responsible for the extinction of aquatic lives and birds.
“Over-extraction of groundwater is reducing the moisture of the soil, killing different grass types. It is alarming for the nation,” he said.
Birds are disappearing due to deforestation, he said, adding that “some unscrupulous people are destroying forests, causing the birds to lose their natural habitat.”
“In the past, village folks were dependent on herbal medicines. Different herbs were used as raw materials for Ayurvedic medicines. It is unfortunate that these ancient herbs have almost disappeared due to rampant deforestation,” he further said.
“Many rivers have lost their flows because of land grabbing. Besides, land-hungry developers are filling up many rivers and wetlands, making it difficult for the rivers and canals to retain water,” Sobhan said.
Changing river course and erosion are gradually cutting off the canals that connect Bangladesh’s primary rivers to the floodplains, causing a significant loss of habitat for small indigenous fish species. These natural causes, combined with man-made destruction, including unstudied cultivation and introduction of exotic, carnivorous species like piranhas and catfish, make for a lethal combination further threatening the survival of indigenous fish species.
-With The Independent input
