Cerithidea cingulata and Littoraria scabra are type of snail that use mangrove ecosystems as one of their habitat. Dumai is one of the industrial cities in the province of Riau, where various kinds of human activities can disrupt the ecosystem of mangroves and its associated biota. This study was conducted in Agustus 2019 in the Mangrove Forest Area Pecinta Alam Bahari (PAB) of Pangkalan S…