عنوان مقاله [English]
Macrobenthos are considered as an important part of sea-bed fauna which include polycheata, creastace and mollusca. Some species are regarded as biological indicators for aquatic ecosystem because of their adaptation with environmental conditions; macro benthos are mostly inhabitants without migration. Thus, impacts of pollution in aquatic ecosystem (e.g. creeks) are served by study of community structure changes. In this study, pollution value has been assessed in Ghannam creek and a part of Mossa creek with adaption of biotic indices and physico-chemical parameters. In the present research, eight stations in Ghanam Creek (a relatively unpolluted river) and the region of Mossa Creek, around the Bandar Imam Petrochemical Company (B.I.P.C) sewage outlet were selected, and water and sediment samples were collected in two seasons: warm (September) and cold (February). Also some indices of water quality such as salinity, temperature, pH and sediment texture were measured . Maximum and minimum of macro benthos density was in winter and summer respectively. Shannon's, Sympson's and Margalof's indices were used for evaluation of macro benthic biodiversity. To access to ecological condition, the Welch Scale (1992) was applied. According to the result of the study, fourteen additional species which were relevant to six classes of benthic invertebrate of brackish and saline water existed. Maximum percentage of invertebrate occured in polycheata, bivalvia, gastropoda, decapoda, isopoda, copepoda, respectively. Lycastopsis sp had the maximum frequency among Polycheatas. Thus, the named species was determined to be considered as the topic bioindicator of water quality. In addition, the result showed that few species inhabited in the stations whose sediment was finer and their organic matter was more than of the stations located in Ghanam Creek. On the contrary, the station far from petrochemical industry (station located in Ghanam Creek) activities had more species diversity. Consequently, a significant relationship between the macrobiotic biodiversity and the percentage of organic matter and sediment texture was seen.