The Tay Foundation is a Charitable Trust helping the River Tay and its tributaries, fish and environment

The Big Challenge...

Tay Foundation Proposal

The Tay Foundation is looking for a major sponsor who can help us develop the river system to its full potential over a ten year period.

Read our proposal and programme of work »

Monitoring salmon stocking

A significant effort is devoted to restocking salmon in the Tay district. The unique Kelt Reconditioning Project is a good example of this.

It is essential if such an effort is made that stocking is evaluated to see how well it works, to identify best methods and best practice and best value for money. Therefore, the Tay Foundation supports ongoing monitoring of stocked areas by electrofishing or other means as appropriate.

A good example of why monitoring is necessary concerns a debate that exists regarding the possible survival rates that can be achieved by stocking salmon as fed-on fry/parr as opposed to eyed ova/unfed fry.

In order to help inform this debate, the Tay Foundation has supported trials at the Almondbank hatchery to compare the survival and growth performance of salmon stocked at different stages.

Starting in 2011 and still ongoing, streams where salmon are naturally absent have been stocked in spring / early summer with eyed ova or unfed fry and again in October with fed-on parr from the same broodstock batches. Follow-up electrofishing surveys are being used to assess any differences in survival, growth or condition.

The first season’s findings proved that, without marking, it is very difficult to tell the two types apart, therefore, the fed fish are now being marked. However, it was clear that fed-on parr stocked in the mainstem of the River Braan, a tributary of the Tay up which salmon cannot ascend naturally, survived well compared to some other trials elsewhere.

salmonstock2
 

The progeny from the Tay DSFB's hatchery and the Kelt Reconditioning Project has largely been stocked out as eyed ova or unfed fry. Follow up electrofishing surveys have been performed to assess survival to the salmon parr stage. These surveys have proved that the offspring of reconditioned kelts can survive like wild fish if planted in a suitable environment.

salmonstock3

As an example, this graph shows how the density of juvenile salmon has maintained a higher level at a regularly monitored site in the River Cononish since stocking with the progeny of reconditioned salmon kelts commenced. The growth rates have also adjusted to a more typical level, indicating that the habitat’s potential is now being achieved.