Relationships between density and diversity of macroinvertebrates and some properties of bottom sediments at different locations, from the coast to Caspian Sea, Gomishan Wetland, Iran

In this study, the effects of sediment texture and total organic matter (TOM) in sediments of Gomishan Wetland on density and diversity of macroinvertebrates were studied. The sampling was carried out in spring (as water-level fall season) and summer (as water-level rise season). The wetland divided to four stations and the samples of sediments and macroinvertebrates were collected from the coast area, near the sea area and water-rise area in each station by Ekman Grab. 10 families were identified which the most abundance was belonged to Pyrgulidae. The sediment texture was different in each location, but Loam was the common texture. Results showed that except of south station, TOM increased from the north to the south of Gomishan Wetland. There were low correlations between the amounts of TOM and silt-clay of bottom sediment with the density and diversity of macroinvertebrates, but the amount of TOM is effective on the distribution of Cardiidae. Totally, the density and diversity of organisms follow complex actions.