[SHILLONG] Scientists have warned that development projects in the northeast of India are degrading rivers and putting fish populations at risk of extinction.
Speaking in Shillong at a workshop that ended on 6 May, the scientists called for more research into the status of the region's fish resources, which are an important source of food and income for local people.
Devashish Kar of Assam University in Silchar said that road and dam building projects in Assam, Mizoram and Tripura states had seriously damaged the ecology of local rivers by removing boulders from the river beds.
Associated tree felling had led to soil erosion and a build up of silt in the river channels, he added.
"The effect is so devastating that we are likely to lose many of our rivers and streams and with it the aquatic life," said Kar.
Viswanathan Waikhom Singh of Manipur University said that the Ithai Barrage, a dam built on Loktak Lake in Manipur, was to blame for the pengba fish (Osteobrama belangeri) becoming extinct locally.
"It blocked the migratory route of the species, leading to its decline," he said.
Wazir Singh Lakra, director of the National Bureau of Fish Genetic Resources, pointed out that non-native fish species that have been illegally introduced into the region's rivers are also posing a threat by out-competing local varieties.
He said that thirty-five species of fish in the Ganges River have drastically declined, while exotic species have thrived, adding that much work was needed to get a clear picture of the status of fish in India.
The National Bureau of Fish Genetic Resources is preparing to launch a network of scientists and institutions to share information.
Also speaking at the conference, the bureau's founder director Punyabrata Das likened the way human activities were affecting fish populations to "digging our own graves".
India's northeastern region, which comprises eight states, is part of a biodiversity 'hotspot' rich in plant and animal life.