Ecological impacts of petrochemical industries on diversity and abundance of macrobenthic fauna in Zangi creek (Persian Gulf).

The Zangi creek is one of the main branches of Moosa creek in the Northwestern part of the Persian Gulf along the Iranian coast. A survey of the Zangi creek was performed, assessing water properties, organic pollution, and the population density, distribution, diversity and biomass of macrobenthic fauna through bi-monthly sampling from July 2006 to September 2007. Results showed spatial heterogeneity in faunal distribution of the Zangi creek. Nine groups of macrofauna were identified from free part of the Zangi creek. Polychaets formed the dominant group (48%) followed by bivalves (13%), gastropods (10%), Decapods (2%), Tanaids (5%), and all other groups (22%). The encompassed creek was significantly polluted with the lack of any macrofauna communities probably as a consequence of the high pH, COD, low salinity and EC. The other stations near to the disposal site were found with macrofauna communities commonly tolerant to organic pollutants. Approximately 2 km east of the disposal site, macrofauna were found comparable to the encompassed creek, even though macrofauna still indicated environmental degradation. Farther a way, faunal density decreases and nonoportunistic taxa gradually replaced opportunistic species, while the otherstations were far from the polluted regions with a low level of contamination provided relatively flourishing macrofauna. Consequently, the results indicated minimum density and biomass in the encompassed creek and maximum density and biomass in 2 km far off the surrounded area. Additionally biodiversity indices were also insignificant in encompassed creek.

کلیدواژه ها:

Moosa creek ، Zangi creek ، petrochemical pollution ، macrobentic community ، Persian Gulf