Applying Benthic Index of Biotic Integrity in a soft bottom ecosystem in North of the Persian Gulf.

In this study, the Chesapeake Bay Benthic Index of Biotic Integrity (B-IBI) was selected in an attempt to describe ecological health of soft bottom channels (Khowr-e Musa) in North of the Persian Gulf. Most of study area was found to be in degraded or severely degraded conditions. B-IBI scores were ranged between 1 and 3.86. Comparison ofmacrobenthos abundance and organic content between two developmental periods showed significant difference (p < 0.05). After the establishment and development of petrochemical industries, the abundance of macrofauna decreased (809 to 239 individuals m(-2)) and organic content increased leading to organic enrichment (15.3 to 22.4%). Three new sources of organic matter were found to be important namely industrial waste, sewage and mangrove litter. After 1999 about 6 millions Avicennia marina tree were planted near petrochemical zone in the area. Study area changed rapidly in the last decade and region is under severely anthropogenic impacts. The present study showed that Khowr-e Musa is under both natural stress and anthropogenic impacts and two main impacts could be attributed to the organic enrichment and to the dredging. Choice of suitable management plans and metric controls could help to the salvage of the largest tidal channel complex in Persian Gulf.