2019 TWEED SALMON SMOLT SURVIVAL STUDY
The Tweed Foundation undertook a pilot study this Spring to track a small sample of Salmon smolts, with acoustic tags, from the Gala Water down to the Tweed estuary at Berwick.
The Salmon smolt is the final product of the river and losses at this stage of the life cycle cannot be replaced. With numbers of returning adult Salmon declining, we need to ensure that as many smolts as possible make it out to sea. 2019’s pilot study aimed to start the process of helping the Foundation’s biologists quantify how many Tweed Salmon smolts make the full journey safely downstream to the estuary. The study wanted to look at:
- How in-river barriers may prevent smolts reaching the sea
- Where smolts get lost in the river, and why
- How river levels affect smolt survival
Acoustic tagging and tracking is an expensive but effective tool for this work, and the Foundation delivered the study with an enormous amount of help from many of those with an interest in the River, who sponsored tags. A weekly blog kept all of our sponsors up-to-date with the progress of the smolts downstream.
The Tweed Salmon Smolt Tracking Report 2019 can be viewed here.
Points to particularly note when reading the Report are:
- Our 2019 study was a pilot project to ensure that the tagging system operated effectively
- We used a very small sample
- The tagging system is unable to pinpoint how smolts which did not reach the estuary disappeared, ie. losses cannot be assumed to be attributable to a single cause!
Based on this pilot study, the Tweed Foundation aims to build on this work with a larger sample of smolts. This larger study will dovetail with other work that is being carried out – both here and on other rivers – to inform future management decisions on the river.
Many thanks to all those who supported the study this Spring.
Further opportunities to help us by sponsoring a smolt will be available for the next phase of the study.