The Tay Foundation is a Charitable Trust helping the River Tay and its tributaries, fish and environment
The Big Challenge...
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.
Salmon Exploitation Study
One of the fundamental requirements for the successful management of a salmon population / fishery is to know the number of salmon in the river and the proportion of these salmon that are caught by fishing.
In the Tay we have been fortunate in that on two of the most important spring salmon tributaries – the Tummel and the Ericht – fish counters have been present for some time and these provide invaluable information on numbers of salmon ascending each year. The results from these counters are often at odds with the numbers which might be inferred from angling catches alone.
However, for most of the salmon which enter the Tay it simply would not be practical to count them in this way. The main stem of the Tay is simply much too big. Since many of the salmon which enter the Tay in autumn spawn in the main stem of the Tay, it has not been possible to quantify the size of this most important run, except by angling success.
One way to help overcome the uncertainties of extrapolating salmon abundance from rod catches is if the relationship between the number of salmon in the river and the rod catch can be understood. In some other rivers this relationship has been quantified by tagging a known number of salmon at the point of entry to the river and then getting anglers to report any tagged fish they catch.
Such studies have been undertaken on the River Tweed, for example, each September since the mid 1990s and have revealed that the number of fish recaptured is generally considerably less than 10%, although in recent years the recapture rate has tended to be higher than it was in the 1990s (see section 6 of the Tweed Foundation Paper). That study has shown that anglers may only be catching a very small proportion of the fish entering the Tweed in the autumn but that increased catches in recent years may in part at least be a result of an increased proportion of fish being caught.
If such a study were to be conducted on the Tay, the most appropriate way of catching fish for tagging would be by netting, as is done on the Tweed. Although the Tay no longer has any operating net fisheries of the appropriate scale (unlike the Tweed), the Tay Foundation, which leases the major net fishing rights on the Tay, could sanction some controlled experimental netting in order to catch fish for tagging and release. Early discussions have taken place with the Tay Salmon Fisheries Company to see if former netsmen might be able to help in this regard.
In order to ascertain the proportion of salmon entering the Tay that get caught by anglers it would be necessary to catch incoming salmon in the upper estuary with a net and then tag and release all fish caught. The information gained would be invaluable in helping inform decisions on conservation measures on angling, particularly in the autumn.