Pontocaspian habitat polygon shapefiles from: Decline of unique Pontocaspian biodiversity in the Black Sea Basin: a review

The unique aquatic Pontocaspian (PC) biota of the Black Sea Basin (BSB) is in decline. The lack of detailed knowledge on the status and trends of species, populations and communities hampers a thorough risk assessment and precludes effective conservation. This paper  reviews PC biodiversity trends in the BSB ( Bulgaria, Romania, Moldova, Ukraine and Russia) using endemic molluscs as a model group. We aim to assess changes in PC habitats, community structure and species distribution over the past century and to identify direct anthropogenic threats. Presence/absence data of target mollusc species was assembled from literature, reports and personal observations. Pontocaspian biodiversity trends in the north-western BSB coastal regions were established by comparing 20th and 21st century occurrences. Direct drivers of habitat and biodiversity change were identified and documented. A pronounced decline of PC species and communities is driven by a) damming of rivers, b) habitat modifications ...