Twit.

Just 3 laps of the lake last night, which is about 2.4k.  It was quite warm and really clear, so much so that I was distracted by assorted fish feeding at the bottom.  There's also seems to be a large number of smaller species swimming near the surface, about 30mm long and probably stickleback sort of size which we used to fish for with jam jars in the local dyke.  If we were luck we would catch a newt, probably making that species even more rare.
You have to swim straight through these smaller fish, who appear to be unaffected by swimmers and never seem to try and get out of the way.  I've never stopped to inspect them, maybe they're bits of weed.  This reminds me of the owl we had perched on a telegraph post that I could see from the house.  After a couple of days of it being there and me telling a few people about our own personal owl, I looked a little closer and realised it was a plastic bag.