These summary statistics and analyses are based on the European freshwater mollusc dataset published in November 2011.
The status of freshwater molluscs was assessed at two regional levels: geographical Europe and the EU 27. At the European level, at least 43.7% of the species are considered as threatened, with at least 12.8% of them being Critically Endangered, 10.5% Endangered and 20.4% Vulnerable. In addition 23 of the 109 Critically Endangered species are considered Possibly Extinct and five species are listed as already Extinct. A further 8.8% of the species are classified as Near Threatened. By contrast, only 22% of the freshwater mollusc fauna was assessed as Least Concern, revealing a proportionately high level of threat to these species.
Within the EU 27, the pattern is very similar: at least 40.9% of the freshwater molluscs are threatened, of which at least 11.8% are Critically Endangered, 8.1% Endangered and 21% Vulnerable. In addition, 8.4% of species are considered as Near Threatened.
|IUCN Red List categories||No. species Europe (no. endemic species)||No. species EU 27 (no. endemic species)|
|Extinct (EX)||5 (5)||4 (3)|
|Critically Endangered (CR)||109 (107)||79 (72)|
|Endangered (EN)||90 (90)||54 (48)|
|Vulnerable (VU)||174 (173)||140 (127)|
|Near Threatened (NT)||75 (66)||56 (46)|
|Least Concern (LC)||190 (109)||172 (65)|
|Data Deficient (DD)||211 (198)||162 (132)|
|Total number of species assessed *||854 (748)||667 (493)|
*This table does not include the Not Applicable species in Europe and/or the EU (species introduced after AD 1500 or species of marginal occurrence). For the EU 27 assessment the Not Evaluated species (species which do not occur in the EU) are also excluded.
The European freshwater molluscs belong to a number of different families, among which considerable differences exist both in species numbers as well as in threatened status. Certain families are of particular concern: the Margaritiferidae, Acroloxidae, Hydrobiidae, Dreissenidae and Amnicolidae are the families with the highest percentage of threat, while the Moitessieriidae, Bithyniidae and Hydrobiidae have numerous Data Deficient species and require further studies.
**Does not include species classed as Not Applicable (NA).