Biodiversity as a tool for environmental assessment

Human activities have induced environmental changes, which, in turn, changed the biodiversity. Biodiversity is the variability among organisms at genetic, species, and ecosystem levels. Biodiversity at species and ecosystem levels can use for environmental impact assessment (EIA). EIA is a tool of environmental management based on evaluating the environmental impacts of a project that propose to reduce the negative impacts and maximize the positive impacts. The biodiversity at species and community levels can be applied for water quality assessment. In the species level, tolerant species will adapt to the environmental changes, whereas sensitive species will move to or be eliminated from the ecosystem. In the level of population, environmental changes will induce changes in the assemblage of organisms. EIA has been conducted in Galela and Pengilon Lakes. Based on the diversity index of phytoplankton, Galela Lake was unstable to a relatively stable ecosystem. The low diversity index related to the dominance of several species found at all sites, such as Aulacoseira granulata, Melosira varians, Synedra ulna, that indicated meso to eutrophic condition. The dominance of genus Eunotia, Pinnularia, and Frustulia indicated the acidic of the corridor of Warna and Pengilon Lakes. Changes in the diatom assemblage reflected the condition of the catchment area.