What next for White-Clawed Crayfish conservation in England?
The White-clawed crayfish (Austropotamobius pallipes) is the only species of crayfish native to the UK, it is one of our largest, most legally protected and culturally significant invertebrates. The species has declined dramatically throughout much of its UK range since the 1970s, in particular due to introductions of invasive non-native crayfish species and associated pathogens. Habitat degradation, pollution and changes to water quality have also contributed to the species' decline.
The White-clawed crayfish, is classed as Globally Endangered by IUCN / WCMC and is listed under both the EC Habitats Directive and the Bern Convention. The UK has a responsibility to maintain the species in a ‘Favourable Conservation Status’.
In the UK it is protected under the Wildlife and Countryside Act 1981 (as amended) and is highlighted as a Priority Species for conservation action under the UK Biodiversity Action Plan (UK BAP).
The White-clawed crayfish has declined rapidly across its global range due to the continued spread of non-native crayfish, in particular the North American Signal crayfish (Pacifastacus leniusculus) which is highly invasive. As a result the UK is now considered an international stronghold for the species.
Action has been taken to address the other causes of White-clawed crayfish decline, including improving habitat quality. Despite this populations are still being lost at an alarming rate. At present there is no known method for the effective, practicable eradication of non-native crayfish from catchments, and a large number of introductions of the species make control a near impossible task.
Put simply, White-clawed crayfish cannot survive where there are non-native crayfish. The species has been lost from much of its historical range, or will be lost in the future, as the invasion of non-native crayfish continues unchecked through most river catchments. Special Areas for Conservation (SACs) have been designated for White-clawed crayfish, but these are not enough to conserve the species on their own. Furthermore, some of these SACs have been compromised or are under severe threat from non-native crayfish.
A Way Forward
White-clawed crayfish face similar threats across the UK, but different approaches are needed for different counties and regions.
A regional strategy for White-clawed crayfish conservation will most often include:
- confirming the status of extant wild populations
- establishing the level of threat to surviving populations
- reduce the risks to these populations where feasible – for example ensuring habitat and water quality, protecting from damaging activities, improving biosecurity and reducing risks of non-native crayfish introductions
- establishing Ark Sites to conserve high risk populations.
An Ark Site for White-clawed crayfish is a safe haven or refuge where new populations can be established, safe from non-native crayfish and crayfish plague. An Ark Site is an isolated self-contained site with running water, still water, or both, which can support a healthy, self-sustaining population of White-clawed crayfish with little need for ongoing management.
This conservation technique has been put into practice by Buglife and the South West Crayfish Partnership which has, over the past five years, undertaken the largest strategic translocation of threatened crayfish to Ark Sites in the UK. And projects by other organisations have established Ark Sites elsewhere in the UK.
While Ark Sites cannot conserve the population abundance of the native crayfish, they can conserve much of the genetic diversity across its distribution and will allow the reestablishment of the local genetic stock back into the rivers when a solution to the signal crayfish problem is discovered.
We recommend that the strategic establishment of Ark Sites for White-clawed crayfish is carried out across England. In the south of the country where Signal crayfish are most widespread this will effectively save threatened populations from extinction; whereas in the north of England this will offer some kind of insurance to the inevitable invasion of non-native crayfish.
Where are we now?
In recent years considerable effort has gone in to preventing the extinction of the White-clawed crayfish, and in to developing Ark Sites as a conservation tool.
In 2012 there were 21 White-clawed crayfish conservation projects in progress in England (information collated by Buglife as part of the development of the UK Crayfish website, in partnership with the Environment Agency). These projects were contacted by Buglife in 2013 as part of a review into crayfish conservation activity in England, and of the nine projects that responded, only two are now funded – these are both catchment restoration projects and only one of these has a focus on White-clawed crayfish. The majority of the project which did not respond were fixed term projects and so it is assumed that these have been completed and have not received further funding.
Funding for White-Clawed crayfish conservation has reduced so drastically that it appears that in 2014 there will be no projects directly saving White-Clawed Crayfish populations and Ark Sites.
The only two projects that we are aware of that are funded, and are directly conserving White-clawed crayfish are the Eden catchment restoration project, and the Hampshire Southern Chalk Streams project – although the latter is greatly reduced in capacity as it has lost its main funding from the Environment Agency.
The Environment Agency has taken a lead role in White-clawed crayfish conservation in the past, and although that level of involvement has gradually reduced, until the more recent cuts the Agency was still leading or at least a major partner in most of the projects. Of the 22 projects listed in 2012, 13 were funded by the Environment Agency, Natural England or Defra. In most of these cases the Environment Agency was the significant funder.
Not only has there been a reduction in funding from the Environment Agency, there has also been a reduction in funding for species conservation work by Natural England/English Nature over the last decade and two of the most significant sources of funding for Ark Site work – The BBC Wildlife Fund and the Aggregates Levy Sustainability Fund – no longer exist.
Funding for White-clawed crayfish conservation has reduced so drastically that it appears that in 2014 there will be no projects directly saving White-clawed crayfish populations and creating Ark Sites.
As an example, the pioneering South West crayfish Partnership has now ended after five years of crayfish conservation action, including:
- Translocating more than 4,000 White-clawed crayfish from 8 threatened populations to 14 new Ark Sites across the region
- Implementing a regional survey and monitoring programme of wild crayfish populations engaging landowners and managers through surveys and monitoring work
- Establishing a captive breeding population (breeding over 1300 crayfish) and public exhibit of White-clawed crayfish at Bristol Zoological Gardens, and a second in planning at Paignton Zoo
- Running an education programme highlighting the threats to White-clawed crayfish and promoting measures for their conservation amongst the public, landowners and key stakeholder groups such as anglers. The outreach programme has reached over 1600 school children and over 2 million other members of the public
- Hosting a national crayfish conservation conference in 2010.
A new regional strategy for White-clawed crayfish in the South West has recently been produced, however there is currently no funding available to deliver the actions needed to secure the future of the species in the region.
Without funding, we risk losing populations in the Lam Brook, By Brook, Little Avon, Creedy Yeo and River Culm in the next five years – this would mean the extinction of the species in Devon. And many more populations are at risk in the longer term.
Considerable conservation effort is required to prevent the extinction of the White-clawed crayfish from English river catchments in the face of the spread of Signal crayfish.
The strategic establishment of Ark Sites for White-clawed crayfish across England is a necessary and pragmatic step in saving the species from extinction.
From the evidence we have gathered, and from our own experience, funding has evaporated, and Ark Site creation is grinding to a halt, leaving populations at risk of extinction.
Community engagement, expertise and momentum are all now at risk of being lost.
Unless new funding is released the White-clawed crayfish is under severe risk of extinction from many catchments across England – losing important genetic adaptations and making the achievement of Favourable Conservation Status now impossible, and in the future more expensive and less likely to succeed.
Article courtesy of : buglife.org.uk 01733 201210 @buzz_dont_tweet Buglife The Invertebrate Conservation Trust is a registered charity at Bug House, Ham Lane, Orton Waterville, Peterborough, PE2 5UU Registered Charity No: 1092293, Scottish Charity No: SC040004, Company No: 4132695