On Saturday fellow club member Dave Pitchers and I carried out our second Riverfly Life survey in the river Wensum. We are part of the Wensum Riverfly Recording programme which is being co-ordinated by Mark Rylands who came and helped us on Saturday. A month after our first survey and with an extra pair of eyes, we increased our score index by just over 50 per cent.
In our second survey we found more species - BWOs, flatbodied upwings and olives - as well as increases in numbers of insects found in April. The only indicator species that we have yet to find is a stonefly. I am pretty sure that I saw an adult stonefly recently but stonefly nymphs are still conspicuous by their absence.
The kick sampling process doesn't take long but sorting out everything produced by the kicking certainly does. It is amazing how tiny some of the nymphs are and little bits of twig suddenly start moving and you realise that it is a cased caddis. And is that little nymph an olive or a small Mayfly?
It's all good fun and very rewarding as well as building a database of scientific knowledge of the invertegrat