Abstract
The distribution of benthic macroinvertebrates in Daecheon stream, an urban stream of Busan, was investigated to analyze the community structure of benthic macroinvertebrates. The collection was performed monthly at five(A~E) sites divided into three parts, upper, middle and lower, of stream from January to November, 2004. In physicochemical analysis of environmental factors, water quality parameters such as BOD, COD, conductivity and ABS were relatively increased in sites B and C. Whereas sites A, D and E showed little variations with good water quality parameters. However, water quality parameters in all surveyed sites showed gradual decrease with time toward improvement of water quality. A total of 8,226 individuals including 4 phyla, 6 classes, 9 orders, 302 families and 44 species were identified from five sites. The most dominant group was insect(class Insecta), and order Ephemeroptera and Diptera among insect was the largest member in species(30.6%) and individuals(75.0%) of benthic macroinvertebrates, respectively. The primary dominant species were Gammarus sp. and Ephemera strigata in site A, whereas Chironomus sp. and Brenchiura sowerbyi were dominated commonly in the other sites. In community analysis of benthic macroinvertebrates of Daecheon stream diversity index showed relatively low values, whereas dominance index was significantly high. Diversity index was the highest in site A, whereas the dominance index was the highest in site B. However, diversity index showed gradual increase with time showing adverse mode in dominance index. From these results, it can be suggested that long-term ecological monitoring of benthic macroinvertebrate fauna is needed for sustainable management of Daecheon stream.