Narrow-mouth Whorl Snail (Vertigo angustior) - Species Action Plan

This tiny snail, less than 2mm in size, favours the tall vegetation growing on wetland habitats, but is not an aquatic species. It also occurs in damp, short grass and moss on marshes, including salt marshes, or among flood debris.
Ref 1/S16 Species Action Plan 16
Plan Author: English Nature
Plan Co-ordinator: English Nature
Review completed January 2003

Action Plan Summary

Current Status

National Status

  • This localised European species is known in the UK from only eight sites in England and Wales, and one in Scotland. It is also known from a further 15 sites in the Republic of Ireland. The snail is nationally and globally threatened and is included on Annex II of the EC Habitats Directive. It is listed as vulnerable on the IUCN/WCMC red list and endangered on the GB Red List 

Norfolk Status

  • Found within the Broads and East Anglian Plain Natural Areas 
  • Three sites: Fritton, Flordon Common and Smockhill in the Tas and Waveney Valleys

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Current factors affecting the habitat in Norfolk

The habitat of this snail is very vulnerable to changes in hydrological conditions, reduced grazing pressure and physical disturbance.

Current Action in Norfolk


Action Plan Objectives and Targets


  • Ensure that all remaining populations are maintained, protected and, if possible, enhanced 
  • Undertake further surveys of former sites and likely sites to determine the current distribution of this species by the year 2000 


  • Ensure that the populations of snails at Fritton and Flordon Common are maintained and enhanced 
  • Undertake survey of former and likely sites to determine distribution by the year 2000

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Management Guidance

(This guidance is a general summary; for detailed information or advice consult the references or contacts below.)

Maintenance of short vegetation of grasses, mosses or low herbs with an avoidance of dessication or flooding.

It is crucial that sites have areas of fen or reed on higher ground to provide refuges when rivers are in flood. Adults floated out of riparian hover during winter flooding do not survive.

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Key Contacts

  • General Information

Roy Baker and Derek Howlett, Wheatfen Partnership, The Ted Ellis Trust, Surlingham, NR14 7AL

English Nature, Wetlands Team, Northminster House, Peterborough, Cambridgeshire, PE1 1UA

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Kerney (1999), Atlas of the Land and Freshwater Molluscs of Britain and Ireland. Harley Books

Killeen, I J (1997). Survey for the terrestrial snail Vertigo angustior at three sites in England (Gait Barrows NNR, Flordon Common and Martlesham Creek). English Nature Research Report 228

Baker et al (undated), Vertigo angustior Jeffreys. A Survey of Norfolk Sites. Unpublished

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