BBC: 'Huge' wildlife loss from sewage plant, charity says
“There has been a "huge" loss of insects in streams because of sewage discharges, according to a conservation charity.
Wildfish surveyed five streams feeding into Windermere in Cumbria and found all saw a loss of wildlife downstream of waste water treatment plants.
The Save Windermere campaign said "everything up the food chain gets impacted" when insects start disappearing.
United Utilities, who run the treatment plants, said they operate "in line" with environmental permits but they are "committed to going further and doing more".
The Environment Agency said it has started reviewing permits for the lake to identify if there is any further action they can take.
The Far Sawrey waste water treatment works lies on the bank of Wilfin Beck, which then flows into Windermere.
The Wildfish survey found an average 75% decline in river fly numbers downstream of the Far Sawrey works.
Surveyors used the three kick sampling method, which disturbed the riverbed and flow of the water and carried the invertebrates down into the net.
They found a 50% decline in insects in the spring and a 100% decline in autumn.
In autumn, surveyors only found two leeches of a single species downstream, which they said shows a serious deterioration in habitat.
At nearby Cunsey Beck, a site of special scientific interest, there is another treatment works called Near Sawrey.
Here, Wildfish found an average 76% decline in river flies below the Near Sawrey works compared to the same habitat type upstream.
Matt Staniek from the Save Windermere Campaign said: “We have data to show [pollution] is actively damaging that lower level of the food chain.
"It then starts impacting the fish, which impacts the kingfishers, the otters, the herons.
"Everything up the food chain then gets impacted when we start seeing these insects disappearing and that’s exactly what’s happening here in a UNESCO World Heritage site and a National Park in what should be the most idyllic place for nature in the entire UK.”
