Each year, the Tweed Foundation run fish traps to study trout spawning populations throughout the Tweed catchment. This is to help us understand the complicated relationship between the Tweed’s Brown trout and Sea trout populations.
The fish traps work by temporarily blocking off upstream passage for migrating fish and channeling most of the water flow through a cage trap. The traps (which are only run during the trout spawning season) are checked regularly so that fish are only temporarily delayed in their spawning migration. Once caught, the trout are measured, sexed, photographed and sampled for scales, before getting released upstream so that they can continue on and spawn.
Since starting in 2000, we have run fish traps in over 10 trout spawning burns throughout the catchment. This has allowed us to start building a picture of where in the catchment spawning is dominated by Brown trout or Sea trout, and where it is a combination of both. In doing so, we are hoping to further our understanding of what factors are at play in determining the distributions of spawning Brown trout and Sea trout in the Tweed and how this influences the Tweed trout fisheries.