Species Composition and Distribution in the Mangrove Ecosystem in the City of Bengkulu, Indonesia

Abstract

Most of the cities of Bengkulu are coastal areas (71.87%) under substantial pressure due to infrastructure development. This condition has affected the mangrove ecosystem and ecological degradation and has induced abrasion. In this study, we aimed to analyze the existing conditions of the mangrove ecosystems in the city of Bengkulu, particularly the composition and distribution of the mangrove species and the determination of the water quality. We collected vegetation data using exploratory methods and direct observation at 13 research sites. We measured the water quality in situ in terms of the temperature, salinity, pH, and dissolved oxygen (DO) at the sites, performed a vegetation analysis, and analyzed the turbidity, total dissolved solids (TDSs), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrate, nitrite content, ammonia, and phosphate concentrations ex situ in the laboratory. We found 52 vegetation species in the research sites, which included 11 true mangrove species, 9 associated mangrove species, and 31 coastal and land flora. A total of 24 species are categorized under the least-concern (LC) category of the IUCN (International Union for Conservation of Nature) Red List, and one species is in the data-deficient (DD) category. We categorized the water quality of the mangrove ecosystems in the city of Bengkulu as relatively good, with all the parameters below the national water quality threshold, except for the nitrite concentration in the Bengkulu River estuary. Proper management needs to be developed for the conservation and restoration of mangrove ecosystems to sustain their functions.