Sewage threat to ‘canaries of sea’

Sewage and animal waste pollution is having a serious impact on UK coastlines, research has revealed.

Scientists from the universities of Cardiff and Swansea analysed the survival of fragile seagrass meadows, often called the “canaries of the sea”.

The flowering plants are highly sensitive to a changing environment, and like the canary in the coal mine, their condition can be used as an indicator of the health of our coasts.

Ten of the 11 sites in the study were in areas with designated EU marine protection. Despite this most of the seagrass meadows were in poor condition, with nitrogen levels 75 per cent higher than global averages.

The meadow with the highest levels was found within the Thames waterway. A seagrass meadow in Studland Bay, Dorset, popular with swimmers, was also significantly enriched with nutrients from sewage. Samantha Herbert