Amir Vazirizadeh

Mangrove ecosystems are known as productive ecosystems with high ecological and economic importance. Anthropogenic effects have destroyed these habitats in many cases. Evaluating ecological and environmental status help to find stress sources in order to conserve them against more destruction. Present study was designed to evaluate ecological health status of Bidkhun mangrove swamp, Bushehr province, Persian Gulf. This habitat is surrounded by industrial establishments and is affected by discharge of urban sewage. Investigating macrofauna structure and calculating ecological indices including Simpson, Shannon-Wiener, AMBI and M-AMBI, were performed to assess its ecological integrity. Sampling was done in six stations during four seasons. Macrofauna and environmental parameter were investigated. Totally 35 macrobenthic species where identified. Polychaeta was the main taxa. There were special and temporal changes in macrofauna composition. Generally, station four, which was located close to sewage canal opening, had different macrobenthic and environmental features. High concentration of nutrients as a result of sewage discharge, have led to algal bloom and decrease of macrofauna density, consequently. Ecological status of present habitat was good or high in most stations but it was poor and very bad in station four. Ecological indices showed that this station is extremely polluted. Besides, invasive freshwater reeds have surrounded the mangrove trees in mentioned station. It is concluded that discharge of sewage is main source of habitat degradation for Bidkhun mangrove swamp. Hence, it is necessary to decrease its impacts by sewage treatment or stopping sewage discharge.