Improving the Accuracy of Atlantic salmon Conservation Limits in SW Scotland

In 2016, the Scottish Government implemented conservation limits with the aim of conserving and protecting Atlantic salmon. Conservation limits are used to assess whether each river in Scotland has enough wild Atlantic salmon eggs available to fill all available habitat accessible to salmon. Conservation limits take into account several factors but currently does not take into account differences in angling effort and exploitation rates between rivers.

In recent decades, Atlantic salmon (Salmo salar) numbers have been declining due to many pressures such as pollution, acidification and barriers to migration. Therefore, in 2016 the Scottish Government implemented Conservation Limits with the aim of conserving and protecting Atlantic salmon. Conservation limits are calculated by a model which takes into account several different factors, such as age of salmon returning to spawn, proportion of salmon which are female and number of eggs required in the river. However, two factors, in the model, which are very important are; rod catch returns and the wetted area in each river available to salmon. Using yearly rod catch returns for each river, the model is run and assigns each river a category between 1 and 3. Category 1 needs no additional management, Category 2 must reduce exploitation rates and Category 3 is mandatory catch and release. Conservation limits are an important tool for effective management of Atlantic salmon but it is complicated and difficult to design a conservation limits model suitable for every river in Scotland due to river differences in salmon characteristics, such as spawning time.

In winter 2017, GFT begun a project which aims to increase our understanding of key aspects of local salmon populations and fisheries in the rivers Bladnoch and Water of Luce. This information could be used to improve the accuracy of assignment in Galloway.

Therefore, the aim of this study is to:

* Collect accurate data on salmon characteristics: Age of smolting, age of return, weight and sex from salmon entering the river throughout the angling season.

* Calculate what percentage of the total salmon population (exploitation rate) is caught by anglers.

* Collect information on angling effort i.e. total fishing time of anglers on each river/beat.

Disappointingly the dry hot summer in 2018 resulted in only low numbers of salmon being netted and tagged.  Useful data has been collected from these fish and the data has been discussed with Marine Scotland regarding how to improve local conservation limits. 

GFT would like to thank the anglers on the Luce and Bladnoch who recorded their angling effort and submitted the information to us during 2018.  From 2019 onwards Marine Scotland requires salmon angling effort to be recorded on all Scottish rivers and submitted with the catch returns for all beats.  The work completed in this study will be useful to help compile methods to ease the collection of the angling effort data as valuable lessons have been learnt regarding what does and what does not work!    

This project was funded by the European Maritime and Fisheries Fund (EMFF) and The Scottish Government.

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