An increasing number of behavioural and genetic studies have shown that the Atlantic salmon is structured into multiple, distinct breeding populations. The evidence shows that salmon in different river systems belong to different breeding populations and stocks in all but the smallest rivers can generally be expected to contain many breeding populations which are reproductively and genetically distinct. In practical terms the Spey will have a salmon population that is distinct from that of other Scottish Rivers and within the Spey, tributaries such as the Fiddich, Avon and Tromie etc will each hold distinct sub-populations.
In the light of this and additional research into the return rates of salmon from the hatchery programme to the rod fishery, the Board reviewed its hatchery operations in 2011. A more targeted approach was developed aimed primarily at areas of the river above impassable man-made obstacles. The area of suitable juvenile salmon habitat above these obstructions was determined and the approximate number of eggs required to stock the area calculated. In turn the numbers of broodstock required was determined and collected from as close as possible to the affected burn during Autumn. The resulting eggs are raised in the Sandbank hatchery in Glenlivet and after hatching are fed through the summer for release into the target areas during September.
To monitor the operation all the broodstock are tissue sampled for genetic analysis and electrofishing surveys are carried out to assess the density of fish established within the stocked areas. Tissue samples from the rod fishery will also collected in the future to assess the return rates as adults to the Spey fishery. Regular updates on stocking activities can be found in the SFB Annual Reports.