Understanding Salmon Population Structures

In particular, the use of SNPs (pronunced 'snips': single-nucleotide polymorphism) has allowed scientists to get a very clear picture of the finer detail of population structuring. SNPs are DNA sequence variations occurring when a single nucleotide in the genome (or other shared sequence) differs between members of a bioloical species or or paired chromosomes in an individual.

The FASMOP (Focusing Atlantic Salmon Management on Populations) project, which has been running in Scotland since 2009, has used SNPs to enable scientists to form a very clear picture of all of the heritable traits shared by salmon not only from a particular river, but from different parts of a particular river.The project has analysed the DNA of fish from more than 240 sites.

One of the very interesting results has been the ability to identify fish with Norwegian DNA - inevitably the desendants of either fish farm escapees or fish which riparian owners accepted from the salmon farming industry in the past, before the deleterious effect of such introductions was recognised.

Mark Coulson of RAFTS and Nick Barker (Ness & Beauly Fisheries Trust) described how genetic profiling has been used to assign fish to their river or origin within the Ness/Beauly catchment with an accuracy higher than 80 per cent. By using SNPs, they should be able to assign accurately down to tributary of origin.

This research has led to some interesting results - such as a notable concentration of fish with Norwegian DNA in a single small river within the system. You can read more about this research here.

Finally, Roger Knight of the Spey Foundation described how ability to identify fish of hatchery origin (down to the level of individual parentage) using genetic profiling has enabled the Spey Board to look in detail at the cost-effectiveness of operating a hatchery, and whether the results support its contnued operation.