Biological assessment with use of HFBI index in Shadegan wetland

This research was done in 6 stationsin Shadeganwetland. Sampling was conducted in spring and summer, with four replications using Peterson grab. During the two seasons sampling, totally 16 species of 5 classesof macrobenthos were counted and identified.Among the identified groupsthe Gastropoda and Bivalvia were most common between two seasons. To understand the ecological situation of the region in terms of pollution, (Hilsenhoff family biotic index (HFBI)usedwith emphasis on organic matters.HFBI indicated the water quality ofstudy area in spring and summer in two classes of poor quality and relatively weak.According to the results of HFBIstations 5 and 6In the spring, ,and stations 1, 2 and 5 in summer showed poor quality, and other stations in the spring and summer classified in weak quality. Results of statistical analysis of HFBI showed that in spring, station 4 is significantly different from the other stations (P