Lead and Cadmium Pollution in the Southern Caspian Sea Basin through Liza aurata using the GIS System

The present study aimed to survey heavy and toxic metal pollution (lead and cadmium) in the southern Caspian Sea basin through Liza aurata using geographic information system (GIS).  Samples of the gill tissue of adult Liza aurata were taken in 10 stations over the southern coast of the Caspian Sea in spring and fall. Interpolation method, Kennedy density function, Moran test, and Gi* index in the GIS were used to determine the spatial distribution, density, zoning and distribution pattern of the metals. The uptake of lead and cadmium was 1.88 and 1.23 µg/g in spring, and 1.42 and 0.79 µg/g in fall, respectively. Analysis of GIS maps showed that concentration and centralization of both metals reduced from East to West. According to Moran test and Gi* index, the distribution of the metals had a strong and hot cluster pattern that reveals the accumulation and closeness of high-density polluted areas. Finally, it can be stated that the pollution of the eastern part of the Caspian Sea (Bandar Turkman and Khajeh-nafs) is higher than permissible international standard limits.