When Beavers – and forests – were common in the Scottish landscape, Salmon and trout would have been restricted in their access into smaller streams by both Beaver dams and natural log jams. The return rates of Salmon from the sea in those days would have been much better than at present : In the 1960’s, when the first tagging of Salmon smolts was carried out, around 1 in 3 returned from the sea as adult Salmon. At present, it is less than 1 in 10, around 7-8%. In population terms therefore,  100,000 adult Salmon would have been produced by just 300,000 smolts in the 1960’s. Nowadays, to produce 100,000 adults needs over 1 million smolts. Juvenile Salmon are, basically, territorial so more smolt production needs more nursery area. Losses of nursery areas due to Beaver dams and other causes would not have been so critical in the past, when marine survival would have been so much better than at present.  However, every square metre of nursery area for Salmon is needed nowadays which is why Salmon Fishery Boards and Trusts spend so much time and money on removing or easing obstacles to fish migration.

Whilst this paper has been prepared by The Tweed Foundation on the basis of information that it believes is accurate, any party seeking to implement or otherwise act on any part or parts of this paper is recommended to obtain specialist advice. The Tweed Foundation does not accept responsibility under any circumstances for the actions or omissions of other parties occasioned by their reading of this paper.