Benthic Fauna of Shadegan Wetland

Biological response and ecological indices of benthic communities, such as greater mortality of foraminifera and shell abnormalities, have been used to document pollution effects on ecosystems. Shadegan Wetland was damaged from a deposition of huge amounts of soot and products of burning oilwells of Kuwait as well as chronic exhaust fumes of refinery and industrial furnaces. In this investigation, community structure and changes in indices of the macro- and meio-fauna of the Shadegan wetland were studied in 2004. Recorded salinity ranged from 4.1 to 63.1 ppt. Salinity varied significantly among sampling stations. pH of the water fluctuated between 6.8 to 8.7. Dissolved oxygen (DO) content of water at the sampling stations ranged from 5.3 to 7.8 mg / l. The maximum and minimum (19.6 and 7 NTU) water turbidities were recorded at the sampling stations 7 and 10, respectively. The maximum and minimum TOM (23.17% and 8.45%) were recorded at stations 3 and 9, respectively. The results of sediment texture analysis showed that soil type in the study area was mostly silty–clay. The highest and the lowest rate of sediment with silty – clay texture were 89.76% and 49.28%, respectively. 18 species of macrobenthos were identified. Gastropods comprised more than 50% of the individuals of macrobenthos populatiopns. Aquatic insects (22%), Crustaceans (11%), Polychaetes and Acaris (each with 5.5%) were the other dominant groups in abundance, respectively. The results showed the highest (984 / m2) and the lowest (26/m2) abundance of macrobenthos were recorded at the stations 10 (Rogbeh) and 8 (Doragh creek), respectively. The results showed that meiobenthos displayed a higher biodiversity than macrobenthos. Ostracodes, Nematods and Foraminifera were the most dominant groups. Many Foraminifera showed morphological shell abnormality. Biodiversity indices (H′ and λ) for macrobenthos and meiobenthos were expectedly different. Meiobenthos, primarily,Ostracodes, Nematods and Foraminifera displayed higher biodiversity than macrobenthos. ANOVA results showed significant variation (P < 0.05) between sampling stations.