Smolt traps
Smolt traps are currently operating in the Laxford and Bhadaidh Daraich systems. No results are currently available, but will be reported as soon as possible.
Manse system
A two-way fish trap was operated at the mouth of the Manse system, North Assynt, from 1998 to 2005. Designed on an existing dam, the trap caught both ascending and descending fish throughout the year.
All fish taken in the downstream trap were tagged behind the eye with a fluorescent dye, a different coloured dye being used in each year. Returning fish were examined for a mark and this was recorded. Similarly, descending fish were also checked for previous tags.
In this way we got an idea of the marine survival rates for the system and also the survival of kelts. The information from the trap was also compared to juvenile surveys within the catchment in a bid to relate the number of juveniles recorded to the smolt run. These data could then be used to examine other systems.
From 2003 the trap was also used as part of a European project managed by St. Andrews University. This was designed to look at the impacts of sea lice and will be reported elsewhere. However, as part of the project the sea trout smolts have been PIT tagged, which gives each fish a unique code and allows individual movement and growth to be assessed.
Sea trout returned to the system for several years after first being tagged.
Fish appear to move in and out of the system, with some descending smolts immediately re-entering freshwater.
Sea trout are still moving into the system in November, during the spawning time.
Kelts are still present in the system in May and June.
Salmon parr and brown trout will move into the estuary for a short period before returning to freshwater.
Trout are moving into the system in February, although not in large numbers, when water temperatures are particularly low.
There are large numbers of salmon smolts leaving the system. However, few returning adults have been recorded
This trap was managed by Cathel MacLeod and Iain MacLeod, who put a lot of time and effort into getting the information, and without whom the project could not have run.
The trap was designed and built by Scott Barnes, with the assistance of Jim Delaney, Lee Thomas and Diane Laird. Thanks to all others who assisted financially and with equipment.
The final report is now available.
