Lake Windermere in the Lake District is turning green, with research indicating a direct correlation with tourists.

Algal blooms are the rapid growth of algae in freshwater bodies, often recognisable by its deep green colouring.

They form as a result of high nutrients, for example from sewage dumping, but also high temperatures. The research company Map Impact, found a link with high temperatures, as a more intense algal bloom developed in the hot spell of 2022.

However there have also been more recent links between high numbers of tourists and intense algal blooms, following research from the Save Windermere campaign group.

There have been some days where over 300,000 tourists have visited the area, compared to the local population of just 35,000.

A warmer summer could worsen the situation in the coming months.