A new phase of research by the Tweed Foundation that aims to investigate ways to improve Atlantic salmon stocks on the River Tweed is under way thanks in part to a £40,000 two-year grant from the Fallago Environment Fund.
The study is tagging 220 young migrating salmon known as smolts and tracking their progress as they make their way downstream.
Increasing marine mortality has seen a significant decline in the numbers of adult salmon returning to Scottish rivers, including the Tweed. Between 1983 and 2016, a period of just 33 years, the numbers of wild Atlantic salmon fell by more than half. To help compensate for increased losses at sea, the Tweed Foundation’s research aims to better understand the factors affecting smolt survival as they pass down the river and investigate ways to minimize losses.
Building on a small pilot study from 2019, Tweed Foundation scientists are using tiny acoustic tags attached to the fish to monitor their journeys and estimate survival numbers of salmon smolts between Galashiels and Berwick. The work will pin point areas where higher losses occur and devise testing methods that identify ways to improve survival. Potential reasons for smolt loss include low river flows, lack of sheltering habitats and predators.