Investigating of the Shadegan Wetland Fish Species Changes in 3 recent decades

This research was investigated in Shadegan International Wetland in different seasons of 1996, 2008 and 2013. In total, more than 15 species of fish were captured and biometeried in Shadegan Wetland. Seasonal sampling was carried out at five stations of Shadegan wetland including Doragh (Mahshahr), Ragbeh, Khorusi, Salmaneh, Attish. The depletion method was used to estimate biomass and was based on the percentage of empty and reduced fish stocks in a confined area. Changes in biodiversity of fish species in Shadegan wetland are occurring in comparison to the year 1996 and 2008 and the species of M. sharpeyi, C. luteus, C. aratus, C. abu and S. Triostegus are increasing and the species of L.vorax and C. carpio are decreasing. In general, S. Triostegus, M. sharpeyi, C. luteus, C. aratus, C. carpio, L.vorax  and C. abu species have the highest fish biomass in the wetland, respectively, and constitute more than 90% of the Shadegan wetland species. Due to the increase in S. Triostegus and C. aratus and C. abu species that have high environmental resistance and decrease in susceptible species such as L.vorax   and T. grypus,  it seems that changing the physicochemical conditions of the wetland will lead to more environmental stress.