Identification and Abundance of Macrobenthic in Estuary of the Gharehsou River

The aim of this study was to investigate the abundance of macrobenthic and their relationship with environmental factors in the sediments of the Gharehsou River and Gorgan Bay. Abundance and distribution of macrobenthic in 12 stations and three regions of Gharehsou River and its estuary, the northern and southern coastal part and parallel to the estuary in the deep part of Gorgan Bay, were evaluated using a Van Veen grab in triplicates during 2018-2019 seasonally. In this study, a total of 4414 specimens of macrobenthic from including 3 phylum, 6 order and 12 families identified. The largest number of microbenthic belonged to Streblospio gynobranchiata (7.35%), then Tubificidae with 24.2%. The lower abundances were also included Pontoporeia affinis (0.05%) and Pontogammarus rubustoides (0.1%). Season of spring with 30% had the highest abundance compared to other seasons. Then the summer season with 29% and the autumn season with 25% were in the next frequency. The lowest frequency was related to winter with 16%. The highest diversity index was in station 4 and the lowest was in station 1. According to these results, it was concluded that the macrobenthic in obtaining and different places have a large limit on the abundance and diversity index. If you use these communities to influence the environment, you have to consider them natural.