Macro-invertebrates in the Wetlands of the Zarrineh estuary at the south of Urmia Lake (Iran)

This research summarizes the data on benthic macro invertebrates collected from 25 points in the urmia Lake wetlands during November 2008 to February 2009. The purpose of the study was to assess the effects of elevated salinity and nutrient (nitrogen and phosphorus) levels on macro invertebrate abundance and composition. A total of 32 taxa were collected, and the common taxa, including Chironomidae (midges), Corixidae (water boatmen), Erythemis (damselflies), Ephemerella (mayflies), Hyalella (amphipods), and snails. Samples at ponds with salinities greater than 10 ppt showed a shift in community composition to salt-tolerant taxa and a reduction in total diversity. The corixid Trichocorixa verticalis, the brine shrimp Artemia partenogenetica, and the dipteran Ephydra are salt-tolerant species that only occur at high salinity levels. Ponds relatively high in nutrients had fewer total taxa, reduced abundance and diversity of aquatic beetles, lower diversity index values, and a greater dominance by chironomids than ponds low in nutrients. It is suggested to allocate about 10 ×106 cubic meters freshwater of the represented rivers to these wetlands to improve their trophic condition and transfer their hypereutrophic waters into the Urmia Lake for more production of the macro invertebrates both in the wetlands and on the lake.