A family of swans from Canvey Lake in Essex, including the mother, father, and their three remaining cygnets, died on Friday after being transferred to South Essex Wildlife Hospital. Residents living near the lake have expressed their devastation following the deaths.
Sue Schwar, founder of South Essex Wildlife Hospital, stated she was "100% sure" the deaths were caused by exposure to blue-green algae. Martin England, a Friends of Canvey Lake committee member, described the situation as an "environmental disaster."
In July 2025, tests revealed Canvey Lake contained 2.5 million cells of blue-green algae per millilitre, significantly higher than the 20,000 cells warning threshold. This finding led Canvey Island Town Council to surrender its lease of the lake to Castle Point Borough Council.
Blue-green algae, also known as cynobacteria, forms a layer of scum on water and is toxic to wildlife. Castle Point Borough Council, which now manages the lake, confirmed recent testing had identified blue-green algae and noted similar issues in other regional water bodies during recent heatwave and drought conditions.
The borough council allocated £500,000 in June for lake restoration, with plans for major works continuing, supported by £1m in funding.