BIOMONTORING OF ENVIRONMENTAL QUALITY OF FISH FARMING PRACTICE AT LAKE RAWAPENING, CENTRAL JAVA BASED ON MACROBENTHIC ASSEMBALGES

Abstract

Over the last decade, the rapid development of fish farming cage system activities at Lake Rawapening has led to the emergence of organic enrichment that may impact on changes in environmental quality. This study aims to determine the environmental quality and level of disturbance in the area of fish farming cages using macrobenthic community structure. Sampling was done in July, October, and December 2009 in three locations: Location I is at area of cages that are no longer in operation (fallowed site), Location II is at a new cage area actively operating and Location III as a reference/control is an area that is not used as a place of fish farming. Random sampling technique was employed in this study. Data were analyzed using ANOVA analysis, the index of species diversity (H'), the similarity type (J'), and multivariate analysis. The results show the variation of physical-chemical conditions over time, but not significantly different between sites. The composition of sediment in both the farming area as well as the reference/control site was dominated by coarse sand (42-47%). Macrobenthic structure differed significantly between sampling locations, but not between sampling time. Macrobenthic community structure at Location I and Location II were generally dominated by opportunistic taxa, particularly the Family Lumbrineridae (23.9%), Capitellidae (22.9%), and Tubificidae (14.7%) for Location I, and Family Thiaridae (28.4%), Turritellidae (25.6%), and Tubificidae (15.4%) for Location II. While at the Location III was dominated by the Family Thiaridae (52.7%). Result from multivariate analysis using Non-Metric Multi Dimensional Scaling (NMDS) indicates that the structure of macrobenthos is more likely to be influenced by the different physical-chemical environment in the three sampling locations. This shows the tendency of differences in species composition between sites during the sampling period.