Welcome To Wirral

1. Current Status

1.1 National

Originally widespread in the lowlands of England and Wales and southern Scotland, but declining and now absent from many of its former haunts.

It is given RDB2 status = threatened, in the National Red Data Book

1.2 Local

Recent post 1990 records from 10 sites in the old county of Cheshire, of which one is situated on the Wirral, a pond at Arrowe Park.

1.3 Legal

There is no legal protection for the species.

2. Current Factors Causing Loss or Decline

2.1 National

Drainage and dredging of its habitats as part of agricultural improvement or occasionally for ill-conceived habitat improvement in the form of producing classic permanent ponds from temporary ponds and marshes. Agricultural run-off that contains poisonous chemicals or nutrients. Fragmentation of habitat leading to problems of re-colonisation as the evidence points to the species dying out for no obvious reason at some sites and it appears to have poor powers of re-colonisation.

2.2 Local

Arrowe Park is owned by Wirral Borough Council whose officers are aware of the importance of the pond where it lives. It is important that all new golf-course managers and rangers are reminded of this as fertilisers on the adjoining golf-course, or use of molluscicides against slugs, or habitat and woodland improvement could be very damaging.

3. Current Action

3.1 National

The importance of temporary and shaded ponds is now better understood and this is in some ways a 'flagship' species for such sites. Its habitat needs are usually acted on when made known to site managers who can influence actions, such as those on publicly owned sites.

Dr. Pat Wisniewski at Wildfowl & Wetlands Trust Martin Mere recently perfected the methodology of captive breeding.

3.2 Local

'Countdown', organised by the Cheshire Wildlife Trust gives details of initiatives within Cheshire.

4. Key Habitats

Lymnaea glabra is found in water-bodies that were in the past regarded as marginal or inferior and of no value and needing converting into usefully productive agricultural land or improving visually for landscape reasons. Such habitats are ponds that dry out or significantly diminish in summer, often partially shaded ponds of that type; ditches that dry out and are shaded are also sites. These are a challenging habitat and may have quite a limited biodiversity - alternatively they are sometimes the rich sites for other invertebrates if they are not too shaded.

The Arrowe Park site is a shaded pond in woodland abutting the golf course. It partially dries out during summer. It seems to have slight water flow through it from the golf course - hence the great importance of ensuring no inappropriate use of chemicals on the golf course. Of interest is that another water snail, the local Aplexa hypnorum, which lives in similar conditions is also found at the Arrowe Park site.

5. Objectives and Targets

5.1 Local

To maintain the population at Arrowe Park.

It might be possible to also attempt introduction into other ponds in the park or to newly created ponds on the site. The snail may have limited powers of dispersal, as it is so relatively infrequent. It may be that it was once more common locally, but only this pond on the agriculturally un-improved land of Arrowe Park remains suitable. A survey of all ponds in the park by Ian Wallace of Liverpool Museum suggested two or three ponds where the habitat seemed similar.

Although the snail is being bred for conservation introductions from stocks elsewhere in Cheshire, efforts should be made to use stock bred from Arrowe Park material to maintain the local gene pool.

5. Objectives and Targets

5.1 Local

To maintain the population at Arrowe Park.

It might be possible to also attempt introduction into other ponds in the park or to newly created ponds on the site. The snail may have limited powers of dispersal, as it is so relatively infrequent. It may be that it was once more common locally, but only this pond on the agriculturally un-improved land of Arrowe Park remains suitable. A survey of all ponds in the park by Ian Wallace of Liverpool Museum suggested two or three ponds where the habitat seemed similar.

Although the snail is being bred for conservation introductions from stocks elsewhere in Cheshire, efforts should be made to use stock bred from Arrowe Park material to maintain the local gene pool.

6. Proposed Actions

6.1 Site safeguard

All land managers at Arrowe Park, and their key operatives, need to be made aware of the need to do nothing to the pond where the snail lives, until better knowledge of how to manage a site for this species is available. To use no chemicals on the adjoining area of the golf course that might be a water catchment area.

6.2 Policy

No information available.

6.3 Land Management

It can be presumed that the heritage landscape of Arrowe Park will be maintained and that the woodland will need managing over time by removal of moribund trees and re-planting. It is important to try and maintain the partially shaded nature of the site. It may need careful removal of accumulated leaf litter at some time, possibly quite soon.

There may be a wish to enhance the pond-scape at Arrowe Park. There are many ponds now of very little wildlife or visual amenity interest where removal of overhanging trees and digging out could be attempted, but the principal way this should be achieved is by digging new ponds.

Whatever method is chosen, efforts must be made to prevent anglers stocking them with fish, and they should be electro-fished to remove such fish if that occurs. 

6.4 Species protection and management

Knowledge of managing sites for this species will accumulate and should be acted upon.

It is possible that a captive rearing programme could be established at the Liverpool Museum Aquarium to enable attempts at introductions to other Arrowe Park sites.

6.5 Advice

Cheshire Wildlife Trust is likely to be the most useful source of advice in the long-term as they will presumably keep abreast of advice about how to manage sites for this species.

If the Liverpool Museum Aquarium takes up this species they could be expected to be an important source of advice.

6.6 Future research and monitoring

The Arrowe Park site should be visited each spring to check that the species is still present; numbers can be expected to fluctuate from year to year, possibly quite dramatically, so population estimates seem unrealistic.

This is an animal that can be told apart from its relatives fairly easily, with a little training; officers of the Cheshire Wildlife Trust or at Liverpool Museum should be able to assist in training of site managers to do this job if needed.

6.7 Communications and publicity

All site managers need to be made aware of the species and where it lives.

There is scope to advertise this as a special species for Arrowe Park, as a 'flagship' for the run-of-the-mill ponds at the site, without indicating exactly which pond is involved. 

Any introductions to new sites could have greater publicity and involve local interest groups.

7. Resources

7.1 National

Maintaining this species is often a matter of NOT doing some land improvement so it can be cost-effective!

There are currently no national initiatives for this species, for which money has been set aside.

7.2 Local

Minor costs within the expected work programme of the site management work force such as more careful woodland management in the vicinity of the pond or minor removal of accumulated litter and scrub clearance around possible introduction sites.

Liverpool Museum might look for support in making a joint approach to funding bodies if it was involved in the programme but it would not proceed with an expectation, at least at present, of direct funding from Wirral Borough Council. 

8. Links To Other Action Plans

All general plans that cover pond or wetland management should note this species and the need to have a suite of pond types from newly dug to advanced shaded.

There are no other species of significant conservation interest that especially like partially shaded ponds that partly dry up, but there are a many that like ponds that partly dry up; the major factor is absence of fish that eat many rare invertebrates and amphibians.

8.1 Conflicts

Potential conflict with landscape management that finds these partly shaded ponds visually unattractive, or that needs major woodland clearance for renewal.

With pond conversions to open deeper ponds; anglers want open deep fish-filled ponds.

No conflict is anticipated with any other conservation plan.

9. Contact Points

Ian Wallace of Liverpool Museum.
Telephone: (0151) 922 7915

Julian Whitehurst, Cheshire Ecological Services
or Gail Butterill, Cheshire Wildlife Trust
Phone: 01270 610180
Fax: 01270 610430