I wrote in early editions of Mollusc World (6: 10; 8: 22) of the UK BAP review process, which was taking place nine years after the publication of the first BAP lists. The review provided an opportunity, using a set of scientific criteria (summarised below), to assess whether the first priority species should retain their ‘priority status’ and also to consider whether further species should be added. All invertebrate proposals were initially sent to the Invertebrate Link BAP Working Group. This body, co-chaired by Deborah Proctor (JNCC) and Nigel Bourn (Butterfly Conservation), considered all proposals and issued a preliminary recommendations list in summer 2006. Worryingly this first list rejected a number of species that the Society considered met at least one of the assessment criteria. These rejects included Vertigo moulinsiana, V. geyeri, V. genesii and Segmentina nitida. Following a short period of further ‘appeals’ (where Martin Willing and Ian Killeen resubmitted revised proposal forms), the ‘final, final, final’ list emerged in late October 2006. In terms of Mollusca, the outcome is very pleasing. All of the original 11 BAP Priority Species remain and all but one of the new candidate species are accepted. The new species add a further eight ‘deserving cases’ to the molluscan priority listings. These additions include the freshwater snails Omphiscola glabra, Valvata macrostoma and Gyraulus acronicus; the freshwater bivalve Sphaerium solidum; the land snails Truncatellina cylindrica and Vertigo modesta, the tidal ditch / estuarine snail Mercuria confusa and the brackish lagoon snail Heleobia stagnorum. These species, together with all of the other BAP proposals, have gone to the Priority Species and Habitats Review Working Group (which includes reps. from the Country Agencies, Wildlife Link, DEFRA, the Scottish Executive and Welsh Assembly) for further consideration. The next step in the BAP process will consider what conservation action is needed for each species by compiling priority actions (separated into 10 categories) required for each species. This process will also include ‘success criteria’ for each species including SMART targets and criteria to assess whether a species might be removed from priority listing. The first steps of this process are to be completed by early spring. For further details visit the BAP website at www.ukbap.org.uk and look at the species and habitats review.
| Glutinous Snail Myxas glutinosa |
3, 4.4, 4.6 | Only known population lives in a single Snowdonian lake. The population is stable, but potentially threatened by eutrophication. | |
| Sand Bowl Snail Catinella arenaria |
1, 4.1, 4.4 | Living on a sand dune complex in North Devon and in calcareous flushes in the Pennines. The snail is at risk in the dune complex as a result of lowered water tables. | |
| Little Whirlpool Ram’s-horn Snail Anisus vorticulus |
1, 2, 3, 4.4 | Restricted to only three main coastal and floodplain grazing marsh areas in southern and eastern England, this may be one of the UK’s most threatened species. One long term risk is from sea level rise flooding many of its sites or raising salinity levels in ditches. | |
| Shining Pond Snail Segmentina nitida |
4.4 | With a broadly similar, but slightly wider, distribution than Anisus vorticulus this is a species that lives in grazing marsh ditches that have not been cleared for many years. The snail has been lost from much of its former range probably as a result of nutrient enrichment. | |
| Depressed River Mussel Pseudanodonta complanata |
4.4, 4.5 | A local species living in the slow-flowing lower reaches of some rivers in southern and eastern England and the Welsh borders. | |
| Fine-lined Pea Mussel Pisidium tenuilineatum |
2, 4.4 | A tiny mussel that lives in fine sediments in some hard water rivers, chiefly in southern Britain. The extremely fragmented distribution and low numbers of this mussel in some rivers is likely to be indirectly associated with high nitrate and phosphate levels. | |
| Pearl Mussel Margaritifera margaritifera |
1, 4.1, 4.3, 4.4 | A long-lived species present in soft-water rivers in western and northern Britain. Declines are due to a wide range of water quality and other factors (e.g. decline in salmonoid host fish, siltation of water courses). Although some Scottish populations are reasonably healthy, those in England and Wales are almost all at risk of extinction. Captive breeding programmes offer one possible ‘last chance’ in these areas. | |
| A Whorl Snail Vertigo geyeri |
1, 4.1, 4.4 | A very local species living in the short, unshaded vegetation of upland calcareous flushes, but also in a few open fens at lower altitudes. This species is found in N. Wales, northern England, East Anglia, eastern Scotland and on one Hebridean Island. Risks for the snail include falling water tables and over-grazing of open hillside sites by sheep and deer. | |
| A Whorl Snail Vertigo genesii |
1, 4.1, 4.4 | A snail with rather similar habitat to Vertigo geyeri, but with a more restricted distribution. It is found very locally in northern England and eastern Scotland and conservation issues are also similar to those of V. geyeri | |
| Narrow-mouthed Whorl Snail Vertigo angustior |
1, 3, 4.4 | A tiny whorl snail found in short, humid turf, often close to the coast. The main centres of distribution are in East Anglia, South Wales and the coast of Northern Ireland, with isolated populations in northern England and western and eastern Scotland. Many of the sites lie close to sea level and are threatened with habitat loss resulting from sea level rise. | |
| Des Moulin’s Whorl Snail Vertigo moulinsiana |
1, 4.4 | This snail occurs in calcareous fens amongst un-shaded vegetation (chiefly sedges, sweet-grasses and reeds) bordering many rivers in southern and eastern England. Isolated outlying populations occur in Wales and south-west England. The chief threat to populations of the snail is probably lowered water tables directly or indirectly linked to water abstraction. | |
| Large-mouthed Valve Snail Valvata macrostoma |
1, 4.1, 4.5 | A species with a broadly similar distribution and habitat to Segmentina nitida. Inappropriate ditch management is one the main risk factors for the species. | |
| Swollen Spire Snail Mercuria similis (= confusa) |
4.1 | A species restricted to the muddy lower tidal margins of a few rivers in southern and eastern England. A snail living in very low salinity waters, it is at risk from barrage schemes and in the medium term, from sea level rise raising salinity levels. | |
| Mud Pond Snail Omphiscola glabra |
4.1 | A local species throughout the country, typically living in shallow temporary pools and ponds, often with few other mollusc species. The species is threatened by loss of marginal land as well as pool drainage or enlargement. | |
| Thames Ram’s Horn Snail Gyraulus acronicus |
3 | A very local species restricted to the upper Thames and some of its tributaries. Water quality changes and excessive water abstraction probably pose the greatest threats to the species. | |
| Witham Orb Mussel Sphaerium solidum |
3, 4.5 | A mussel currently only known to live in the UK in the lower reaches of two rivers in eastern England. In both systems, numbers are declining and there is strong circumstantial evidence associating this decline with eutrophication. | |
| Whorl Snail Vertigo modesta |
4.1 | A whorl snail restricted to small areas of arctic-alpine vegetation on mountain summits and plateaus in eastern Scotland. It may be at risk from increased visitor pressure in these upland areas disturbing the small areas of low, slow-growing vegetation where the snail lives. | |
| A Chrysalis Snail Lauria sempronii |
A snail restricted to two old, ivy covered walls in the Cotswolds. Disturbance of these old walls poses the obvious threat to the species. | ||
| Cylindrical Whorl Snail Truncatellina cylindrica |
3 | A very local species found in short, dry, calcareous grassland, often in lose friable stony ground. It occurs at scattered sites in eastern England and Scotland and is threatened by land management changes. | |
| A Spire Snail Heleobia stagnorum |
4.6 | A snail living in brackish, non-tidal ditches and lagoons; it is confirmed living in one area in southern England. A species threatened with salinity changes and water quality deterioration. | |
| English Chrysalis Snail Leiostyla anglica |
A species widespread in a range of wetland and woodland habitats, chiefly in western and northern Britain. A ‘near endemic’ to the UK and Ireland. | ||
| Silky Snail Ashfordia granulata |
A species widespread in a range of humid, usually unshaded habitats throughout most of Britain. A ‘near endemic’ to the UK and Ireland. | ||