Print Shortlink

Tweed BioBlog – Wednesday 24th October: Europe and the Leithen

Wednesday 24th October: Kenny out at TweedStart, teaching schoolkids how to fish, James analysing electric-fishing data from the Summer. I started the day with more work on our six monthly report to Europe for our part of the Living North Seas programme. It’ s not just listing what we have done, we also have to provide evidence that we have done what we’ve said we’ve done e.g. photos of me giving talks, tagging fish etc. In the afternoon, out to check the Peebles trap – no fish, but we know now that it needs a particular, rather high, water flow for fish to get up to this trap. Checked the mouth of the Leithen on the way back – the electric-fishing results for this tributary were down this year, and below the cauld as well as above it. In the early 1990s, major work was done to to give the Leithen a downstream-pointing and deep connection with the Tweed, but this has now all gone. There is a huge delta of stones now, the constructed channel is all filled in, and the Leithen is back to having an upstream-pointing and rather shallow connection witth the Tweed. In low flows, access would now be difficult for fish, which is doubly unfortunate as the fish pass in the Leithen Cauld, upstream of Innerleithen, is best for fish passage at low flows, but poor at  high, when the fish can get through the mouth. Not a good situation, but as nothing long-lasting can be done where gravel is so mobile, its the fish pass that needs to be improved.