Uncontrolled fishing seems to cause disturbance to the avian visitors at Valankulam and other tanks of Coimbatore city. According to environmentalists, fishermen are adopting crude methods to chase large flock of native and migratory birds that come to the water bodies for their share of fish.
Though a large number of Spot-Billed Pelicans (Pelecanus philippensis), listed as near threatened species in IUCN Red List of Threatened Species, had landed in Valankulam last week, a majority of them were chased away by fishermen. Apart from crackers, they also beat the water using wooden planks or sticks to scare birds as well as fishes after laying nets.
A fisherman told The Hindu that hundreds of big birds (pelicans) had landed in the water body and they could easily deplete their livelihood, if stayed for long days. Fishermen, who used to lay nets during weekends in the tank, have now started casting net on a daily basis as the water level has increased in eastern and western sides of Valankulam. Though located in close proximity to the city, Valankulam is home for nearly 100 species of birds.
“Common visitors to the tank like Painted Stock (Mycteria leucocephala), Black-Headed Ibis or Oriental White Ibis (Threskiornis melanocephalus) and Spot-Billed Pelicans are near threatened species. Cormorants, Oriental Darter, Kingfisher, Heron and Egret are other common species spotted. With a large number of birds depending on the tank, at least a specific area should be marked for them limiting fishing,” said R. Mohammed Saleem of Environment Conservation Group.
Singanallur Lake is another tank witnessing uncontrolled fishing though it was declared as Urban Biodiversity Conservation Zone by the Coimbatore Corporation in July 2016.
According to volunteers of Centre for Urban Biodiversity Conservation and Education, a group involved in conservation activities at the water body, use of crackers to scare birds is rampant at the Singanallur Lake. Compared to Valankulam, researchers had recorded 170 species of birds, including 40 migratory birds, at Singanallur Lake between 2004 and 2016. Of these, seven are near-threatened species.
Meanwhile, Mr. Saleem pointed out that catching fish from the tanks itself is a risky business as they are grown in water polluted by heavy metals and toxins.
“For fishermen, fishing is their livelihood. But consumption of the fish caught from these tanks is not at all safe as untreated water and effluents are discharged into them,” Mr. Saleem said.