Heavy metal concentrations in the selected tissues of the Persian sturgeon, Acipenser persicus, from southern coast of the Caspian Sea

Bioaccumulation of heavy metals, including Cd, Pb, Cu and Zn in muscle, gill, liver, kidney and stomach in Acipencer persicus was studied. Fish were collected from the 'Iranian fishery zone 1' located between Astara and Kiyahshahr across five stations in the study area during the autumn catch season in 2001. Samples were analyzed by wet digestion with hydrogen peroxide and nitric acid. Analyses were testified using spike method. A sample of bovine liver (CRM 185R) was also tested to ascertain reliability of analyses. Digested samples were analyzed using Flame Atomic Absorption Spectrophotometer. The bioaccumulation pattern for Zn in different tissues studied was stomach > liver > kidney > gllls > muscle tissue. The mean concentration of Zn in the stomach was 136.6 +/- 10.70 mu g g(-1) dry weight. Cu with the maximum concentration of 39.71 +/- 8.85 mu g g(-1) dry weight in liver showed a bioaccumulation pattern of liver > kidney > stomach > gills > muscle tissue. The bioaccumulation pattern for Pb was determined as gills > liver > kidney > stomach > muscle tissue. Maximum mean concentrations of Pb 6.87 +/- 2.25 mu g g(-1) dry weight belonged to gills. Bioaccumulation pattern for Cd in the different organs studied in A. persicus was kidney > liver > gills > stomach > muscle tissue. Maximum mean concentration of 5.1 +/- 0.97 mu g g(-1) dry weight belonged to kidneys and the minimum mean concentration of 0.05 +/- 0.007 mu g g(-1) dry weight belonged to muscle tissue. Concentration of the metals in the muscles samples were below the most guidelines for human consumption. However, the concentrations for heavy metals were higher than duidelines in some other organs this does not pose health problems as these organs are not used for human consumption.