We have been working away behind the scenes to put in place everything needed to monitor smelt output from the catchment above the dam. We know numbers are critically low as only a handful of salmon have made it through the dam in the last 3 years.
The view from the dam today. The female Osprey was sitting on eggs in the nest and we caught a glimpse of her head from the Roundhouse Cafe’s scope.
We suspect one of the main problems at the dam is that smolts struggle to find the exit from the loch to the lower river. This may be due to limited draw at the entrance to the fish pass and we hope to work with Scottish Power to ensure that the most suitable draw down doors are always open. There would be little point in expecting smolts to find an open door that’s 5m below the surface. Getting this right may solve just one aspect of the problem. We are about to install smolt curtains in the loch to assist any remaining smolts to find their way into the ladder. These curtains will funnel smolts towards the open draw down doors.
In the coming years we will also be inserting PIT tags into smolts in the burns above the dam and monitoring their passage through the loch and the ladder where they will automatically be recorded. Any smolts that survive to adulthood and return to the loch will be recorded as they pass the receiver in the ladder. We should be able to tell exactly where these returning adults originated and which burns are most productive. Of course other factors will influence productivity and we will be looking at SEPA’s pH data collected remotely to see how this compares between burns.
We will insert a receiver and decoder into the fish pass shortly one we agree the method with Scottish Power. The fish pass at Loch Doon Dam appears to be well designed and constructed and leads us to believe that the problem lies with the entrance doors at the loch.
This work will inform management of where problems lie and where improvements need to be made. Pragmatic management aimed at restoring productivity in one third of the catchment. Hopefully will will have acted just in time to prevent the total loss of these salmon and their genes.
