The study of benthic community structure and protein expression pattern of four benthic species in effluent areas of sewage treatment plants in Kaohsiung, Taiwan Dwi Candra Pratiwi Advisor: Dr. Li-Lian Liu Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung, Taiwan, R.O.C. Abstract In order to gain better understanding on the impacts of sewage treatment plant (STP) effluent on marine environment, the present study was undertaken to investigate the structure of benthic community and protein expression patterns of 4 benthic species in STP effluent areas in Kaohsiung, Taiwan. Six sites were selected, 3 near Jhong Jhou STP, 2 near NSYSU STP and one reference site. Samples were collected in December 2009 (winter) and July 2010 (summer) by bottom trawling. In winter, temperature was 26.8oC; salinity and pH were 32. 2‰ and 8.1. In summer, environmental data were 33.7oC, 31.5‰ and 8.0, respectively. In all, 5 phyla, 31 families and 48 different species were captured in two seasons. Proteomic approach by one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D SDS-PAGE) was conducted on 3 fishes, Leiognathus splendens, Apogon fasciatus, Engyprosopon multisquama, and one crab Portunus hastatoides. Environment characteristics and structure of benthic community had no significant difference among the 6 sampling sites. Protein expression patterns based on the four examined species also indicated no significant difference among sites. The complexity of pollutants in Kaohsiung Harbor is probably the main reason affecting all sampling sites. In other words, contaminated area in Kaohsiung Harbor may cover a wide range, at least III over the present sampling distance, i.e. 8km which causes no difference in community structure and protein expression pattern among control, Jhong Jhou STP and NSYSU STP sites. Key words: 1D SDS-PAGE, Leiognathus splendens, Apogon fasciatus, Engyprosopon multisquama, Portunus hastatoides