Smolt Trap Update

April 18, 2016

The traps have been operating for the last 3 weeks, and both are operating very well. We had initial concerns with the Sheeoch trap – owing to its size, it needed a stronger flow of water to turn the heavy drum which we weren’t getting initially, however, it is now operating continuously .

So far, on most days, there have been a handful of salmon smolts in each of the traps, but there have been a few days when we’ve seen a few hundred smolts in each trap. The total as of 17###sup/sup### April is 431 salmon smolts in the Beltie and 478 smolts in the Sheeoch. We think it is early days in the smolt run yet, so we are delighted with these numbers - based on other rivers in northern Scotland. We are expecting our smolt run to peak towards the end of April and we expect to see numbers increasing this week – dependent on good conditions for migration.

There have also been some sea trout smolts in the traps (41 in the Beltie, 23 in the Sheeoch) and a surprising number of juvenile brown trout – over 1000 in the Beltie and over 500 in the Sheeoch. This we were not expecting, as these fish are not migrating like the smolts.

Last week we also had sufficient numbers of fish in the trap to start marking some of the fish with a blue dye, to look at how efficient the traps are at catching fish. These dye-marked fish are released upstream of the trap, and then we look for how many we recapture. So far, indications are that we have high recapture rates of around 70%, which is incredibly high and gives us confidence that we are going to be able to estimate quite robustly the smolt output in these 2 tributaries.