HUBUNGAN KEPADATAN SIPUT (Drupella) DENGAN KONDISI EKOSISTEM TERUMBU KARANG DI PERAIRAN PULAU SEMUJUR PROVINSI KEPULAUAN BANGKA BELITUNG: THE RELATIONSHIP BETWEEN DRUPELLA SNAIL DENSITY AND THE CONDITION OF THE CORAL REEF ECOSYSTEM IN THE WATERS OF SEMUJUR ISLAND, PROVINCE OF BANGKA BELITUNG ISLANDS. AKU 2019, 13 (2), 152-161. https://doi.org/10.33019/akuatik.v13i2.1498.