Indigenous species of fish die

May 31, 2013

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.
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.
“Owing to the thin flow of water in common rivers originating across the borders, rivers and other water bodies are drying up.
The Farakka barrage is a major threat for the survival of fish and other aquatic species in the Ganges-Padma and its tributaries. As the flow of water in rivers keeps decreasing, siltation is also increasing, resulting in destruction of fish habitats,” Sobhan noted.
The government should introduce new laws to protect the country’s biodiversity, he suggested.
Global climate change has also become another threat hanging over Bangladesh’s biodiversity. The country, now seriously pondering over the negative impact of global warming and global climate change, had paid little attention when scientists cautioned about the fast change in the earth’s climate, experts noted.
In Narayanganj, various species of fish die and float into Brahmmaputra River at Langalbandh area under Bandar upazila of Narayanganj, a holy place of Hindu devotees as toxic waste is dumped into the river indiscriminately. The color of the clear water of Brahmmaputra River has turned black with a bad smell.
Locals alleged that different species of dead fish were found floating upon the surface of the river for several days.

-With The Independent input

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