EXISTING CONDITIONS OF GASTROPOD COMMUNITIES IN AREAS AFFECTED BY OVERBURDEN NICKEL MINING IN THE MANGROVE ECOSYSTEM OF DAWI-DAWI, SOUTHEAST SULAWESI

Abstract

Gastropod resources in the Dawi-Dawi mangrove ecosystem, Southeast Sulawesi are greatly influenced by the input of overburden wastewater from nickel mining activities. This condition has been going on for the last 2 decades and has degraded the habitat and structure of the gastropod community. The upstream connectivity associated with the existing nickel mining area and the Dawi-Dawi River estuary mean that the mangrove ecosystem in this area is continuously affected by overburden runoff. This research was carried out in June-August 2023 in the mangrove ecosystem of Dawi-Dawi Village, Southeast Sulawesi Province. This research aimed to determine the existing condition of mangrove gastropods affected by overburden. This research began by conducting initial observations in the field, to identify mangrove ecosystems affected by overburden. Research stations were determined using a purposive sampling technique and sampling of gastropods was carried out by using a simple random sampling method. The ecological index of mangrove gastropod community affected by overburden showed a tendency for a medium diversity index (H’ = 1.81), low species richness (R = 1.42), high evenness index (E = 1.12), and no dominance of certain species (C = 0.19). The gastropod species found were of typical types that made up the mangrove fauna, namely Terebralia sulcata, Terebralia palustris, Faunus ater, Telescopium telescopium, Hebra nigra, and several taxa of climbing Littoraria snails which were found in the roots, stems and leaves of mangroves. The abundance of gastropods obtained was also very low, namely around 0-12 ind./m2. At some points (rarely) schools of small snails of the type T. sulcata (5-21 ind./m2 ) were sometimes found. This research showed that overburden waste eliminates or reduces the diversity and richness of gastropod species in the mangrove ecosystem of Dawi-Dawi.