There is a huge bloom of millions of Daphnia in the lake at Diamond Jubilee Wood near Heather. It is a fascinating sight. Shovelers going round in circles. I think they are hoovering them up. I expect it is happening in all the shallow lakes where ducks gather and poo and make water eutrophic.
Apparently there are a few different species of Daphnia!
In addition to being food for many animals they also stop the water going green with algae.