On Tuesday, while inspecting the restoration works on the River Peffery, Simon McKelvey and I were fortunate enough to see a sea trout spawning! As we were approaching one of the V-log structures we saw the bow wave of a significantly sized fish that was too big to be a Peffery brownie and was almost certainly a good sized sea trout. The fish darted off as we approached but soon came back and on closer inspection we could clearly see the clean turned over gravel and slight hollow that were the beginning of a trout spawning redd. This fish was upstream of the Scottish Water weir and this sighting provides good evidence that the works done on the weir to ease passage for migratory fish are working and sea trout can now get upstream, at least in some water levels, to access the extensive habitat available upstream. It is also excellent evidence that the in-stream structures are proving effective at improving habitat and specifically the spawning gravels which were previously compacted. These V-log structures were installed in over widened and straightened sections where the bed is often compacted and there is little habitat diversity. The upstream pointing V made of sycamore logs focuses the energy of the water in the middle of the channel excavating a pool and depositing clean gravel downstream while also trapping gravel upstream where this particular trout was cutting its redd.
The V-log structure is on the right and the clean gravel that the trout has turned over while cutting the redd can be clearly seen upstream the structure on the far side.