REDUCING pollution in Lough Neagh has had the unwelcome consequence of contributing to the dramatic decline in its water birds, it has been claimed.
The number of diving ducks migrating to the lough, which is the largest lake in Britain, has dropped from 100,000 to fewer than 21,000 in the past decade.
The dramatic decline has been blamed on climate change and a 66% reduction in the amount of insects and snails living on the lake bed.
Dr Irena Tomankova, who led the new study at Queen’s University in Belfast, said: “Historically the lake was heavily affected by organic pollution as a result of nutrients from agricultural run-off. This artificially boosted its productivity.
“Now that conservation schemes are beginning to have an effect and reduce levels of pollution, we are seeing increasing water quality and the unexpected consequence is fewer invertebrates and as a result less duck food.”
Lough Neagh, a designated Special Protection Area, is situated in the centre of Northern Ireland with five of the region’s six counties touching its shores.It measures 300 square kilometres and contains more than 800 billion gallons of water.
Wintering wildfowl fly in from places such as Canada, Iceland, Greenland and the Russian Arctic.
However, the Queen’s researchers said changes in the lake’s ecosystem since 2000, coupled with the effects of global climate change, had led to a huge decline in the amount of food available for migrating birds.
Earlier this year it was revealed that the numbers of some key water bird species had dropped throughout south-western Europe while increasing in north-eastern Europe. This has been attributed to rising winter temperatures - up 3.8 degrees Celsius over the past 30 years - and means that lakes which were once frozen during winter are now available for birds to feed on.
Less food in Lough Neagh and more ice-free lakes closer to the birds’ natural breeding grounds mean that ducks do not need to fly as far south-west. As a result, Lough Neagh has lost some of its importance for overwintering water birds, researchers said.
Ian Enlander, from the Northern Ireland Environment Agency (NIEA), said: “It is critically important for conservationists and policy-makers to understand the reasons behind the dramatic changes that have been recorded at Lough Neagh.
“This work has been an outstanding contribution to improving our knowledge for this site. It underlines the need for international conservation measures to apply across the entire range of these migratory species.”