PROTECTING & IMPROVING THE TAY
Easing Fish Passage over Weir at the Den of Alyth
In the course of the Lowland Burn Survey in the winter of 2009/10, Board staff found a large weir in the Alyth Burn in the Den of Alyth. While the weir is not high enough or steep enough to be a complete barrier to migrating salmon it was thought that under most conditions it might be.
This view was then tested by electrofishing in the summer. While both salmon fry and salmon parr were found downstream of the weir, no fry were found above it. Although parr were found above it they did not extend far upstream in numbers. Some salmon must have managed to ascend the weir in 2008 but none could have in the cooler winter of 2009.
The survey also revealed that the Alyth Burn has excellent habitat for juvenile salmon for a considerable number of miles above this weir and ought to be a very productive stream for salmon.
We are developing ideas to make this weir more easily passable to salmon.