The resident ecologist at Norton Mills lake has said that people's lives were put at risk by the person or people who shot to death the geese and swans.
Brian Morland said that police believed a large calibre rifle was used to shoot the birds through the wings and legs.
More top news
Police have said it is "highly unusual" for teenager Emily Wicking to go missing. They are asking hotels and B&B owners for any information.
A look ahead at the forecast for the Tyne Tees region.
Tony Blair's former bodyguard has been found guilty of benefit fraud after raking in tens of thousands of pounds in disability allowance.