Rudd, for better or worse!
8th January 2010, FridaySpeak to someone about bittern conservation and the chances are you will be advised to stock a water body with rudd, because they provide them with a good food supply. Unfortunately Workhouse Pond, in Northiam, has also been stocked with rudd, not to provide bittern food, but as an apparent “conservation project”. A few years back the pond in the summer was covered in duckweed, giving it a pea-green appearance. It also supported all three species of newt, with good numbers of smooth and palmate.
Then people started to complain about the state of the pond and it was eventually cleared out a few years ago. Duckweed is one of those annoying plants that is very difficult to eradicate. You just need one tiny piece and before you know it it has proliferated and covered the water surface again, so I did not expect success. The pond was drained and dredged, and miracle of miracles, on refilling it stayed clear. So I decided to investigate by trapping it last year.
The result was no great crested newts captured, and very few smooth or palmate newts. What I did find though was large numbers of fish, including a lot of rudd. These are a very predatory species and ponds I have surveyed in the past few years that supported them have held very low densities of amphibians. They appear to be one of the few fish species that eat distasteful natterjack toad tadpoles, so they are not discriminating. Goldfish were also present. I suspect it is the fish that have kept the duckweed at bay, so good if you hate duckweed, bad if you like amphibians.
But what is the relevance of this post now, surely it is about 9 months out of date. Well, we are going through a spell of prolonged frosty weather. In such conditions the water can go anoxic killing fish, if the ice lasts a long time and the pond contains a lot of decaying vegetation. The pond is not a large one, and small ponds tend to be more prone to this problem that larger ones. It will be interesting to see if any fish do survive, and then to see what happens to the amphibian populations. Whatever, I doubt we shall be seeing bittern in this part of Northiam, sadly!