The presence of blue-green algae on Coniston Water has been confirmed by the Environment Agency (4th July 2018). Whilst not all blue-green algae is toxic you can’t tell whether it is or not from its appearance, so please follow the advice from both the Environment Agency and the Lake District National Park Authority.

Avoid coming into contact with it, don’t swim nearby and keep children and pets away from it too. As with any pollution incident please report sightings of algal blooms to the Environment Agency on 0800 807060

https://www.gov.uk/government/publications/algal-blooms-advice-for-the-public-and-landowners/algal-blooms-advice-for-the-public-and-landowners#algal-blooms-in-inland-waters

http://www.lakedistrict.gov.uk/caringfor/policies/algae

There’s a wide range of blue-green algae (cyanobacteria). In fresh waters , they’re suspended within the water or attached to rocks and other surfaces  but you usually can see them when they’re concentrated into clumps.  It may become green, blue-green or greenish-brown and several species can produce musty, earthy or grassy odours. Blooms can also cause foaming on the shoreline – sometimes confused with sewage pollution. Not all are toxic but it’s best to be cautious.