stream thought

North Country Angler reports the sighting of a beaver on the Tummel in Scotland. Groups such as the Scottish Beavers Network  (SBN) are advocating re-introduction of the European Beaver and cite anglers as being opposed to re-introduction because beaver dams would reduce fish mobility.

 On the one hand I would love to see wild beavers in Scotland. On the other hand I think it is right that we should proceed with caution and test the impact that re-introduction would have on flora and fauna. The reports by the the SBN on increased insect life and therefore more feeding opportunities for fish are one sided and unbalanced. We should fairly judge the activities of beavers based on proper research.

Studies seem to show  complex interactions between beavers and trout. The warming of waters caused by increased exposure of streams to the sun (caused by beaver tree felling), the leaching of coniferous plantation soil into the watercourse, reducing oxygen content, the deposition of silt in ponds and slower water and its effects on insect ecology, the effect of freeze on ponds and its impact on trout spawning, the potential restriction of trout away from their upstream spawning sites - there are some potential negative effects. Also there are some positive effects such as more holding water for trout, more minnows in warmer water, more diversity of fauna and so on.

It is possible that the beaver spotted by North Country Angler is an escape from one of the trials?