Detecting Levels of Environmental Disturbance from Fish Farming Using Multivariate Analysis

Environmental disturbance of water ecosystem, both natural and anthropogenic, may affect sediment structure, which macrobenthic animals inhabit. This study aims to determine environmental disturbances caused by aquaculture, through linking abiotic parameters and macrobenthos community structures. A coastal area of Menjangan Besar Island, Central Java was researched, between August and November 2018. A systematic, random sampling method was used by collecting three stations from both: Location I (monoculture sites) and Location II (reference sites). Sampling occurred twice, with a sampling interval of two months. Non-metric Multi-Dimensional Scaling (NMDS) of Bray-Curtis similarities and k-dominance curves represented visually the differences between sites over time. To assess the environmental disturbance at each station, EWS-3SWJ software was introduced. Results were acquired using NMDS by location and sampling time. They indicate a tendency of grouping, and hence a degree of difference in macrobenthos community structure response, spatially and temporally. The results of the k-dominance curve at the R3T1 (Reference site; second sampling time) and station M3T1 (Monoculture site; first sampling time) are at the top. This indicates the dominance of a species from Anodontia sp. Both locations are classified as moderately disturbed areas, owing to the strong current and organic nitrogen level