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28 January, 2015

New report on beaver effects on salmon and trout

A report looking at at how salmon and trout populations might be affected, if beavers are reintroduced to Scotland, was published today (28 January).

The Scottish Government will decide later this year whether to reintroduce beavers to Scotland, after receiving the results of a number of studies, including the five-year Scottish Beaver Trial in Knapdale, Argyll.

The report was produced by the Beaver Salmonid Working Group (BSWG), which is made up of specialists from the fish biology, fishery, wildlife and river management sectors. The report was prepared for the National Species Reintroduction Forum (NSRF).

The report found that there would be a range of impacts on salmon and trout as a result of beavers, and although further research is required, any successful reintroduction would depend on a management plan.

The report also found that beavers may affect salmon and trout positively by, for example, increasing the number of invertebrates available for fish to feed on, as well as increasing the variety of habitat for fish, including areas for rearing, overwintering and avoiding fast flows. However, negative impacts may include beaver dams sometimes limiting salmon and trout moving along waterways and the loss of valuable spawning habitat.

Ron Macdonald, NSRF chair and Scottish Natural Heritage’s (SNH) Director of Policy & Advice, said:

“We’re grateful to the BSWG for this comprehensive and useful report, and we’ll examine their recommendations carefully. The report will form an important part of the information that SNH is gathering for the Scottish Government for late May. We recognise that there are evidence gaps on the impact on salmon and trout and that, if the Scottish Government approves reintroducing beavers, a management plan will be required to quickly address any potential problems.”

BSWG chair, Roger Wheater, added:

“The BSWG recognise that beavers may benefit biodiversity in the Scottish countryside, but beaver dams on small rivers and streams may also, under some circumstances, create barriers to migratory fish, including the iconic salmon and trout, thus denying them access to their spawning areas. Our report has indicated that if beavers are to be reintroduced, clear and unequivocal management plans are needed. Without such plans, any possible benefits to salmonids from beavers may not be realised. Further research and monitoring of wild beavers will be essential as an aid to further planned releases and their management.”

For the full report, see


Media queries – contact Roger Wheater on or 01896 830 403.

Or contact SNH media & public relations officer Vicki Mowat, on 0131 316 2659 or (Tues to Fri) or the Inverness press office on 01463 725 022 (Mon).

Notes to editors

The Scottish Beaver Trial: In May 2008, the Scottish Government gave permission to the Royal Zoological Society of Scotland and the Scottish Wildlife Trust for a scientifically monitored, trial reintroduction of European beavers to Knapdale Forest in mid-Argyll. SNH is co-ordinating the independent scientific monitoring of the trial. For more information on the trial, see . For more information on the scientific monitoring of the trial, see .

The Beaver Salmonid Working Group (BSWG) is chaired by Professor Roger Wheater. The membership of the group includes the Association of Salmon Fishery Boards, Marine Scotland, National Museums of Scotland, Scottish Government, Scottish Environmental Protection Agency, and Scottish Natural Heritage. The BSWG was formed in 2009 as a sub-group of the National Species Reintroduction Forum (NSRF), as migratory salmonid fish were not routinely present within the Knapdale site. The BSWG’s remit is to consider the potential impact of beavers on Atlantic salmon andtrout. This report will form a significant part of a wider package of information which is being collated to inform the Minister on all aspects of beavers and beaver reintroduction issues.

The National Species Reintroduction Forum (NSRF) is chaired by Scottish Natural Heritage and has a membership representing a range of stakeholders from land use, conservation and science sectors. The overall role of the Forum is to contribute to broad scale, strategic issues relating to species reintroductions and other types of conservation translocations in Scotland. Further information is available at .

Contact information

SNH Media

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Salmon: Please credit SNH/Lorne Gill.


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