Concentration of heavy metals in different tissues (muscle, liver, gonad, skin, kidney) of Roach (Rutilus rutilus caspicus) in Guilan coasts of the Caspian Sea

The study was conducted to determine the concentrations of some elements and heavy metals including aluminum, cadmium, chromium, copper, nickel, lead, strontium, silicon, arsenic, antimony, cobalt, manganese, molybdenum, iron and zinc in edible (muscles, gonads) and non-edible tissues (Liver, kidney, skin) of the Caspian Roach (Rutilus rutilus caspicus) caught from the Caspian Sea in Guilan Province. 65 fish were collected from 3 fishing regions e.g. Astara, Anzali and Kiashahr from 2017-2018. Digestion process followed standard method procedures. Samples were digested and concentration of elements was measured by ICP-OES Perkin Elmer Optima 8300 atomic absorption spectrometer using standard Australian Geostats solution. Mean concentrations of Al, As, Cr, Cu, Fe, Mn, Sb, Si, Sr, and Zn were 1.007, 0.3, 0.33, 2.21, 12.78, 0.57, 0.78, 1.26, 1.97 and 11.5 μg/g respectively. Concentrations of Cd, Co, Mo, Ni and Pb were not detectable. Iron, showed significant difference in various tissues (p <0.05), but other metals did not differ significantly between tissues (p <0.05). Metal selective index (MSI) was Fe> Zn> Cu> Sr> Si> Al> Sb> Mn> Cr> As. Comparison of metal concentration with international standards showed that muscles of Rutilus rutilus caspicus is healthy for consumption. However, if metal contamination of the Caspian Sea is not managed, there is high potential for metals concentration exceed the safe levels. National and provincial decision makers, especially the Environmental Protection Organization (EPO), should invest more resources and control over industrial and agricultural activities, as main paths for pollutants entering the Caspian Sea. Severe and appropriate measures should be taken to make them comply with environmental standards.