AN INFLUX of cormorants is destroying trees and eating fish from South Lakeland’s rivers and lakes, anglers claim.
Observations show the protected bird has significantly increased in numbers over the past three decades.
But a wildlife charity fears that cormorants are now being ‘demonised’.
To combat the growing numbers, the Angling Trust has launched Cormorant Watch, a website where people can record where the birds are found.
Several locations have been marked in Cumbria where colonies are living, including Killington Lake between Kendal and Sedbergh, the River Kent, Lake Windermere, and a site close to Wythburn, off the southern tip of Ullswater.
A 150-bird colony has also been spotted in Raisbeck, near Tebay.
The birds have been sighted at Bolton-le-Sands and Roeburndale in North Lancashire, Garsdale in North Yorkshire, and areas in Cumbria including Drybeck, near Appleby, Kentmere, Esthwaite Water, Marton near Lindal-in-Furness and Great Urswick.
“This website is trying to gather information to take to Defra to show the problem that we have got with cormorants, and goosanders,” said Chris Preston, secretary of the Kent (Westmorland) Angling Association.
“They’re living on fish and we’re trying to protect the environment to get more fish spawning to improve the quantity of fish in the rivers and lakes.
“But our efforts are being defeated all the time by the growth in the number of these types of birds.”
Bare trees have also been found at Killington Lake, which occurs because cormorant droppings are toxic.
Fears are growing that the Lake District could end up like Lithuania’s Neringa National Park, where hundreds of trees have died since the first cormorants nested there in 1984. But authorities can do nothing to stop them because of their status as protected birds.
Cormorants have the same status in Britain.
Neil Harnott, senior conservation officer at Cumbria Wildlife Trust, said: “It is a beautiful bird and a graceful fisher that has had a place in human mythology for many years, including being a good luck charm for fishermen,” said Mr Harnott.
“They are a native species that is an important component of the biodiversity of Cumbria and one that deserves our continued protection.
“There are concerns among some that declines in some fish species, such as salmon and eels, are linked to this increase in cormorant numbers but there is no evidence to support this claim.
"For all native fish species, declines are likely to be driven by wider environmental issues.
“We are also concerned that the continued demonisation of this species could lead to an increase in illegal persecution.”