| Comment | Well, that was remiss of me.
It's a blue-green shimmer on the surface of the water, as seen [here](https://canalrivertrust.org.uk/refresh/media/image/42036.jpg?w=900&fm=webp&s=e92f008d9636ac3dfa1b361100cf6d0e) and [here](https://canalrivertrust.org.uk/refresh/media/image/42069.jpg?w=900&fm=webp&s=552d43d5738c79908abcb5c44670861e) ([full article](https://canalrivertrust.org.uk/enjoy-the-waterways/safety-on-our-waterways/blue-green-algae-what-you-need-to-know)). |
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