Beaver Information Exchange for Wales: Frequently asked questions

Frequently asked questions: Impacts

How would cost of beaver impact compare with that of other wildlife?

Deer damage to agriculture alone in England has been estimated at £4.3 million, or £33 (€47) per km2 per annum (Wilson 2003). Rabbit damage has been cited as £44 (€63) / km2 per annum for Britain (Rees 1985) depending on the incidence of myxomatosis.

In contrast to this, the Swedish government has concluded that their 100,000 beaver have no economic impact on a national scale.

The Norwegian Forest Owners Association don't consider damage to timber is significant enough to insure against. Equally, fisheries authorities, also in Norway, where there is a valuable salmon sport industry, consider there is no need to fund research given the minimal impact by beaver.

Can we reasonably assess the short, medium and long term impacts of beaver on species, ecosystems and landscape?

Yes. There has been plenty of research on mature beaver populations of both species that give us information on the impacts of beavers on other wildlife and the riparian landscape.

Much of this has been reviewed in the scientific paper: Rosell et al (2005) Ecological impact of beavers Castor fiber and Castor canadensis and their ability to modify ecosystems . Mammal Review 35:248-276.

Will the presence of beaver on a river affect the Catchment Management Plans and Flood Risk Management?

Beaver would not be reintroduced to any river catchment if it is thought likely that there would be any significant adverse impact on the delivery of Catchment Management Plans and Flood Risk Management strategies.

There is no substantive evidence that beaver cause significant flood damage. Indeed, in many instances, the effects of beaver on a river catchment can lessen the impact of flooding by slowing water down and reducing sediment load. Where local flooding occurs (e.g. through blocked culverts) this can be readily prevented or managed.

Beaver structures can alleviate pollution, by increasing oxygenation and retention of colloidal materials [ Rosell et al (2005) Ecological impact of beavers and their ability to modify ecosystems. Mammal Review 35:248-276.]

Will beaver adversely affect the features of designated sites such as SSSI and SAC?

Any reintroduction would need the approval of the WAG and CCW who have responsibility for SSSI and SAC designated areas.

Beaver reintroduction would not take place if significant damage to the integrity of statutorily protected areas was likely to occur as a result, and any incidental occupation by beaver can be easily dealt with by removal as described above.

Overall, beaver reintroductions in Europe have demonstrated substantial benefit in enrichment of riparian woodland and wetland habitats, diversifying ecological niches and increasing numbers of attendant bird, mammal and insect species.

Could beavers affect current agri-environment management agreements that farmers and landowners may have entered into?

Agreement would be reached with WAG, CCW and other regulatory bodies to ensure that agri-environment schemes would not suffer as a result of beaver reintroduction.

This should for example include protection of payments for riparian planting where this is subsequently impacted by beaver.

The Welsh Assembly Government and CCW will need to approve any reintroduction plans before they are enacted.