Turloughs are karst wetlands unique to Ireland. We sought to elucidate mollusc community composition across a broad range of turloughs and to establish the major factors determining spatial distribution and community composition to better inform management decisions. Quantitative pond-net surveys for molluscs were conducted on Carex nigra dominated vegetation zones at each of eight turloughs. Surveys were conducted at each site twice – once just after flooding (early) and once before emptying (late). Thirteen other homogeneous zones were surveyed in the same way once, to assess relationships with environmental variables over the full hydrological gradient. The abundance of temporary-wetland specialists was significantly higher in the early as compared to the late samples, but late samples were more dissimilar to each other than early ones. Site was a more effective grouping variable than time of sampling for the Carex nigra community, and this effect was even higher when considering the whole hydrological gradient. The idiosyncratic nature of the turlough mollusc fauna was notable in both the indicator species analysis and the nestedness analysis. Results suggest a blanket approach to the conservation of turlough molluscan faunas is not appropriate and that turloughs should be considered individually when developing management recommendations.