August 17th – I see there are patches of scum on the canal again in various spots. These seasonal bands of detritus are ugly, but are organic in origin – usually pollen, blossom debris or seed mast. 

I couldn’t work out what was generating this one, and it’s sporadic, but suspect it’s connected with nearby trees.

It’s a sign of the much cleaner times that such events are now so noticeable.