Evaluation of trace elements contaminations in muscles of Rutilus kutum (Pisces: Cyprinidae) from the Southern shores of the Caspian Sea

There is little information about the trace elements (TEs) concentrations in the muscle tissue of Caspian kutum (Rutilus kutum) in the South Caspian Sea.

A total of 51 R. kutum specimens were caught at five fishing stations (Gorgan, Sari, Kiashahr, Anzali, and Astara) in the South Caspian Sea from September 2018 to January 2019. The inductively coupled plasma-optical emission spectrometry (ICP-OES) was employed to measure the
TEs concentrations in the fish muscles.

The maximum concentrations of Al (7.2 ppm), Pb (0.07 ppm), and Ni (0.02) were reported in Astara, and the highest concentrations of As (0.2 ppm), Cu (0.49 ppm), Cr (0.12 ppm), and Zn (1.56 ppm) were reported in Sari and Gorgan. The TEs concentrations measured in the fish muscles (except Mg, Zn, As, Al, Na, and S) had no significant differences among the sampling areas. The TEs concentrations were higher in the eastern areas (Sari and Gorgan) than in the western areas (Astara, Anzali, and Kiashahr) excluding As and Al. The concentrations of Pb, Zn, Mn, Cu, Sn, Sb, Al, Cr, and Cd in muscles of R. kutum were found to be significantly lower (P < 0.05) than the maximum permitted levels according to the WHO/FAO standards, while As concentrations were comparable to these standards.

The TEs concentrations in different fishing stations of Kiashahr, Anzali, and Astara, located in the southwestern areas were respectively compared with those obtained from Sari and Gorgan, located in the middle and southeastern shore of the Caspian Sea. According to the results, the TEs concentrations obtained from the fish muscles cannot pose a threat to human health.