MUD SNAIL (LYMNAEA GLABRA)
LOCAL BIODIVERSITY ACTION PLAN
ACTION COMPLETED IN 2005
Detailed study of distribution of mudsnails and other molluscs initiated in certain ditches at Gowy Meadow. New find of mudsnails in a pond at Gowy Meadow.
OBJECTIVES
To establish distribution and halt and reverse the decline of the mud snail population.
LOCAL TARGETS
Targets awaited
CURRENT STATUS
The mud snail (Lymnaea glabra) is a west European species of local distribution. In Britain it was formerly fairly widely distributed throughout the acidic lowland areas of England, Wales and Scotland as far as Perth. It is now rare, with the largest concentration of records coming from the southern part of the Vale of York.
This species has become extinct over large parts of lowland England and shows continuing decline. A three year survey (1995/6/7) of 370 ponds in the Cheshire region found the mud snail to be present in only three ponds. (Pond Critical Biodiversity Survey: 1997).
The mud snail is listed as vulnerable (RDB 2) in the British Red Data Book; a category for taxa believed likely to move into the Endangered category if the causal factors continue operating.
THREATS
- Drainage or dredging of wetlands, ditches, ponds and seasonal pools.
- Ploughing and other agricultural practices leading to chemical or organic enrichment causing eutrophication of water bodies through leaching and run-off.
- Inappropriate management, such as is frequently carried out in the name of 'conservation' for the benefit of more common aquatic species.
- Fragmentation of habitat, thus decreasing or preventing colonisation or re-colonisation.
CURRENT ACTION
- Chester Zoo held Mudsnails displaced from Manchester airport development, and is now in negotiation to take snails from a development site near Rochdale - these snails will be released back into new habitat at the development site once it has been created and allowed to settle.
- The remaining population at Manchester Airport is being monitored as part of the mitigation programme.
- Records held by rECOrd
- Ditch rotational management plan being implemented at Gowy Meadows to protect and enhance current population.
ACTION REQUIRED IN 2006+
- Form a Local BAP Action Group for the mud snail.
- Survey to establish distribution in the Cheshire region.
- Identify the criteria for, and implement, a recovery programme for this species.
- Raise awareness of the mud snail and its habitat requirements.
- Continue distribution studies at Gowy Meadow, to determine effect of managenent activities; possibly colonise other ditches deemed suitable.
ACTION COMPLETED PREVIOUSLY
- Three new colonies were discovered in 1998 near Nantwich. The colonies have been protected as part of a mitigation scheme for a new housing development.
- Surveying at Gowy Meadows in 2002 identified a new population.
- The extent of the population(s) at Gowy Meadows was established in 2004.
ACTUAL LBAP IMPLEMENTERS
| Cheshire Wildlife Trust |
Manchester Airport PLC |
rECOrd |
| Chester Zoo |
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OTHER POTENTIAL IMPLEMENTERS
| Borough and Parish Councils |
English Nature |
Museums |
| Cheshire County Council |
Landowners and managers |
Universities and Colleges |
| Conchological Society of Great Britain |
Local groups and individuals |
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CONTACT
Mike Tynen, Cheshire Wildlife Trust
Phone: 01270 610180
Fax: 01270 610430
REFERENCES
JNCC (1991): British Red Data Book 3, Invertebrates other than insects.
HMSO (1995): The U.K. Steering Group Report, Volume 1.
Kerney (1976): Atlas of the non-marine mollusca of the British Isle
Date compiled - 1998
Date reviewed - 1999, 2000, 2001, 2002, 2004, 2005
The Wirral Biodiversity Action Plan for mud snails can be seen at www.wirral.gov.uk/ed/biodiversity/msnail.htm
