With winter over, the month of March is start of the year of activities and research for LLFT. It begins with the smolt monitoring programme. The Loch Lomond Fisheries Trust deploy two rotary screw traps continuing the smolt monitoring programme within the Endrick Water catchment area. The long term monitoring of Atlantic salmon and sea trout smolts on the Endrick and Blane Water provides us with annual estimates of smolt production which can be used to influence conservation management.
Late March is the time when the first smolt rotary screw trap is placed into the Endrick Water. In 2016, the river channel changed over the course of the winter so the trap was positioned about 20m upstream from the original site as the river channel. The trap seems to be working very well. Many thanks to all those who gave up their Saturday to help launch the trap, to those who helped choose its new location and to Mr Bilsland for kindly allowing us access once again.
In March 2015, there was substantial rainfall, with the Endrick Water rising by 11 feet in one night. This resulted in the rotary screw trap nearly being destroyed by debris being washed downstream. Luckily our dedicated volunteers were on hand and managed to save the rotary screw trap. Smolt migration peaked early in 2015 and with the rotary screw trap under repair, lower numbers of smolt were caught when compared to previous years.
Our rotary screw traps were used to capture Atlantic salmon smolts for an innovative fish tracking project being led by Professor Colin Adams and Hannele Honkanen based at the Scottish Centre for Ecology and the Natural Environment, University of Glasgow. In the UK, this type of Salmonid smolt tracking has primarily been carried out in river systems, however this project plans to answer questions relating to the movement of smolts through large bodies of freshwater such as Loch Lomond before they reach the seas.
The section of river we have used in previous years for the rotary screw trap has changed significantly due bank erosion and this site is no longer suitable so a new location is to found. is to be found. The locations chosen need to be easily accessible, have anchor points we may use and should channel the smolts into our traps. We have decided to deploy both traps on the Endrick water this year to increase our chances of getting enough large Salmon smolts for the smolt tracking project. This project has been developed by Prof Colin Adams and Hannele Honkane who are associated with the IBIS project (Integrated Aquatic Resources Management Between Ireland, Northern Ireland and Scotland) and the University of Glasgow. This will be the second year that the Loch Lomond fisheries trust has been involved with this project.