Narrow-mouthed Whorl Snail (Vertigo angustior)

Whorl snails are tiny snails with outgrowths known as 'teeth' at the entrances to their shells, with these teeth designed to protect inside the shell from predators. The arrangement of these teeth is the key way to identify different whorl snail species apart. Narrow-mouthed whorl snails (Fig. 1) are generally found in areas of dune/coastal grassland or marshland (Buglife, n.d.).

Range & Distribution:
Along the Aberdeen and Aberdeenshire coast this snail has only been recorded near Stonehaven, at two areas close to each other known as Garron Point and Red Man Bay (Fig. 2).  These are the most northern populations in the UK (NatureScot, 2005), with an approximate density of 2750 snails per square metre at Garron Point and 1500 snails per square metre at Red Man Bay in 2019 (Killeen, Willing & Moorkens, 2019). The only other known location of a narrow-mouthed whorl snail population in recent years in Scotland is White Port on the Solway coast.

Due to erosion of vegetation, it is believed that the species has now been lost at the Red Man site. The population at Garron Point appears to be stable.

Factors affecting Narrow-Mouthed Whorl Snail:
Change or loss of habitat are one of the biggest factors affecting the populations of narrow-mouthed whorl snails, particularly natural processes such as habitat succession or coastal erosion (Littlewood & Stockan, 2013). Change and decrease in water quality is also a threat to these snails (Buglife, n.d.).

Conservation Status:
UK Biodiversity Action Plan: Priority Species (BRIG, 2007)
Scottish Biodiversity List: Priority Species (NatureScot, 2020)

Killeen, Willing & Moorkens (2019) found that White Port is no longer a likely location to find these snails. This means the Aberdeenshire sites are now likely the only place to find this species and are therefore very important locations for this species in Scotland.

Conservation Efforts:
The area where the snails are located is protected under the Nature Conservation (Scotland) Act 2004 and the Habitats Regulations (1994), as Garron Point is designated a Site of Special Scientific Interest (SSSI) and a Special Area of Conservation (SAC) in part due to the presence of the narrow-mouthed whorl snail population (NatureScot, 2005; NatureScot, 2008).