Introduction of Beavers Create Threat to Salmon

"These claims are entirely demolished by the publication of an exhaustive forensic analysis by the Tweed Foundation of the available scientific research on the subject", says the Tweed Foundation.

Nick Yonge, Clerk to the Tweed Commission, commented: “Over recent months we have become increasingly concerned by the continual and flawed statements declaring that beaver dams will have no negative impact on our native fish. A complete picture has hitherto not been presented and there has been a highly selective use of the available research. Unfortunately there is a great lack of understanding by those who wish to introduce beavers on numerous aspects of beaver and fish interactions. For example, there is complete ignorance of the conditions that salmon and trout require in order to leap obstacles”.

Mr Yonge continued: “In order to set the record straight the Tweed Foundation has researched and now published the facts as they stand. The findings are detailed and factual. Whilst beavers are zoologically very interesting animals, that interest largely stems from their ability to change the habitat in which they live, from one kind to another, by making dams. These dams create instream ponds and flood the land above them. Whilst this suits some species, it does not suit our native fish which are mostly migratory and need to move up and down our rivers.

"Instream obstacles hinder that movement. Before embarking upon trials to introduce beavers, a full assessment is required of what their effects will be upon our rivers. There may be benefits but there will certainly also be damaging effects, such as to fish. To understand this properly we need to know what the capacity is for beavers in Great Britain, say in 50 years time, and then match that with the changes we know they can make. An estimate could then be made of the cost of controlling beavers which has to be undertaken in all other countries with mature beaver populations. Only then can a rational decision be made to introduce beavers to Britain or not”.

Andrew Douglas-Home, Chairman of the Tweed Commission, added: “Beavers may well be resourceful creatures with beneficial implications for some species. However we are highly concerned that the pro-beaver lobby has thus far conspicuously failed to give informed responses to our fundamental concerns about the impact of beavers on migratory fish. "The beaver protagonists have consistently maintained that beavers and beaver dams are entirely beneficial to fish populations. However this is simply not borne out by the available scientific evidence which the Tweed Foundation has now drawn together and published. The literature shows conclusively that beavers can have a severe negative impact on migratory fish – particularly their ability to access spawning tributaries – with inevitable consequences for future fish numbers and thus employment levels on Scotland’s rivers”.