By Henrietta Appleton, GWCT Policy Officer (England)
In early 2021 Dylan Roberts, our Head of Fisheries, wrote a blog on the reintroduction of beavers entitled “Environmental Engineer or a waterway menace?”. With the launch of the Species Reintroduction Task Force and in particular calls for beavers to be released freely into the wild getting louder, we felt now was a good time to revisit this often-controversial subject.
I last wrote about species reintroductions in England in early March when the current Secretary of State had indicated that lynx and wolf reintroductions would be ruled out. Species reintroductions are viewed differently in the devolved nations and so it is important to emphasise that the points below relate to England. The GWCT as an organisation is supportive of species reintroductions provided that the International Union for the Conservation of Nature (IUCN), and Defra’s associated guidelines, are met.
We submitted evidence to the EFRA committee’s inquiry on Species Reintroduction and so have taken an interest in the oral evidence sessions, particularly those with Dr Andy Clements, Chair of the Species Reintroduction Task Force, Natural England and the Minister.
There is clearly great enthusiasm for reintroductions as a conservation tool and in some situations, mainly plants, the process causes little controversy. However, quite rightly the Minister suggests that reintroductions should be part of the conservation toolkit with the emphasis on habitat – and we would add the need to urgently conserve our dwindling existing wildlife rather than wait for it to become extinct.
The Defra Code and the Importance of Impact Mitigation
Of particular note was the role of the Defra code, based on the IUCN guidelines for reintroductions. The code is voluntary in many cases and is only mandatory where a species is listed in Section 14 of the Wildlife and Countryside Act 1981. Section 14 refers to an offence being committed if the release is of a species “not ordinarily resident” or a “regular visitor” and included in Schedule 9. This schedule includes some native species that have the potential to cause conflicts such as the beaver.
This emphasises the value of adhering to the code over issues such impact mitigation, an area of considerable debate with regard to beavers as the title of this and the 2021 blog suggest. The GWCT has often expressed concern that many reintroductions do not have sufficient regard to the on-going monitoring of the impact of the reintroduced species – both at the release site and further afield.
Beavers as Ecosystem Engineers: Benefits and Positive Impacts
So what of the benefits of beavers? They are called ecosystem engineers as they can alter the dynamics of rivers and streams through building dams and so can naturally restore river function by:
- Regulating water flow
- Storing sediment
- Reducing woodland density around waterways
- Improving habitat diversity
- Changing the amount of slow and fast flowing water in rivers.
The deep pools and glides they create benefit minnows, sticklebacks and lamprey; provide feeding and resting areas for brown trout ; and support pond loving creatures like frogs and newts whilst encouraging the ‘restoration’ of wetland plants.
Evidence from beaver enclosures suggest that the ponds can also store sediment and associated nutrients and pollutants washed in from farmland and therefore benefit downstream water quality, but this has not been tested in the wider landscape. Importantly for many, these actions hold back water limiting downstream flood risk in prone areas. For many these benefits outweigh any downsides.
Challenges and Considerations for Wild Releases of Beavers
But when considering wild releases, the Minister needs also to be aware of the challenges that naturally dispersing beavers can present. In the recent EFRA inquiry these challenges were considered to be part of us renewing our co-existence with beavers. But a lot has changed in our landscape since the beaver became extinct in the 16th century and the risk they pose to some of our critical infrastructure such as flood defences (ironically) should not be ignored. Who will cover the costs of future-proofing our infrastructure against beaver problems?
The example of flood mitigation exemplifies the fact that the benefits and costs of beaver reintroductions may not accrue in the same place and therefore to the same stakeholders. This is a conflict that a national strategy for beaver reintroductions (and other mobile species) could seek to address, and therefore give comfort to those impacted beyond the initial release site that there is recourse for damage recovery and control.
In many countries, beavers are actively managed to control numbers and mitigate impacts: in Latvia and Lithuania (respectively 25% and 15% of the area and population density of the UK) beaver populations are 70,000-120,000, and 20,000 to 30,000 are culled (shot) annually under a hunting licence. But in England the protected status of beavers makes their control difficult.
The Way Forward: Addressing Concerns and Establishing a Comprehensive Licensing Regime
Currently, a landowner/manager needs to apply for a licence if there is a need to modify or remove a dam, modify or remove a burrow/lodge and capture, transport and re-release beavers. According to Tony Juniper as part of wild releases there will be guidance on a post-release hierarchy of interventions such as limiting dam size and a last resort option under licence for lethal control. To date the licensing of the lethal control of a protected species (for example in response to a conservation need) by Natural England has been difficult to achieve. Stakeholders will need to have confidence in the licensing system.
With regard to the potential broader biodiversity impacts the GWCT is concerned about the impacts of beaver releases on access to breeding grounds in the headwaters and tributaries of rivers by migratory salmon and sea trout. The River Otter Beaver Trial that has been used as the basis for reviewing the implications of a reintroduction was focussed primarily on the benefits of beavers, including to the rural economy, eco-tourism and some biodiversity impacts but largely did not collect information which may have highlighted negative effects.
As a result, we along with a number of other fish conservation stakeholders commissioned an independent review of wild beaver impacts. The report emphasised the need for beaver management in fish conservation and for more research to understand the interactions between beavers, their dams and migratory species of fish in particular and concluded that further releases should be put on hold, before we risk further damage to populations of wonderful fish that are already in a parlous state because of human activity.
So to answer the question posed at the beginning – are we any nearer to knowing whether the beaver is an environmental engineer or waterway menace? Quite simply no because the question requires a black and white answer. Instead, the question we should be asking is “in this location would the reintroduction of beavers be a net benefit?”. But to answer this question we need to have confidence in the assessment process; something sadly we do not have.
In order to give all stakeholders the necessary confidence in the system, we believe that a future licensing regime should consist of 3 elements: it should require all reintroductions/ translocations to be scrutinised, balance benefits and risks and allow lethal control as a last resort.
1. The response of a brown trout (Salmo trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification (cdnsciencepub.com)