en Ecology Ecology پژوهشي Orginal research papers <span lang="TR" style="font-size:11.0pt"><span style="font-family:&quot;Calibri&quot;,sans-serif"><span style="color:black">In this study, the bioaccumulation of eleven metals (As, Fe, Hg, Zn, Pb, Se, Cd, Cr, Cu, Mn, and Ni) in the muscle tissue of 25 Caspian kutum (<i>Rutilus frisii kutum</i>) collected from the Siah Darvishan River, Guilan Province, Iran, during the summer of 2016 was investigated using varian atomic absorption spectroscopy. The mean concentrations of the metals (&micro;g g⁻&sup1; d.w.) ranged as follows: Zn (34.87&ndash;36.12), Fe (29.15&ndash;33.34), Cu (7.57&ndash;8.84), Mn (1.89&ndash;2.23), As (0.80&ndash;0.87), Pb (0.73&ndash;0.88), Se (0.68&ndash;0.80), Cd (0.25&ndash;0.28), Ni (0.27&ndash;0.32), Cr (0.15&ndash;0.16), and Hg (0.08&ndash;0.09). According to the results, the mean concentrations of all elements in the muscle tissue of Caspian kutum were below the threshold limits recommended by FAO/WHO international standards, except for Mn (2.045&plusmn;0.169), As (0.840&plusmn;0.038), Pb (0.805&plusmn;0.077), and Cd (0.265&plusmn;0.011).</span></span></span> <span lang="TR" style="font-size:11.0pt"><span style="font-family:&quot;Calibri&quot;,sans-serif"><span style="color:black">Overall, the results indicate that the consumption of Caspian kutum from the Siah Darvishan River does not pose a significant health risk to consumers. Nevertheless, continuous environmental monitoring and regular assessment of metal contamination are essential to ensure long-term ecosystem health and food safety.</span></span></span> Environmental contamination, Trace elements, Toxic metals, Metal pollution 863 876 http://jifro.ir/browse.php?a_code=A-10-2211-3&slc_lang=en&sid=1 M. Ettefaghdoost ettefaghdoost@phd.guilan.ac.ir 100319475328460059639 100319475328460059639 Yes Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, 1144, Guilan, Iran A. Babakhani 100319475328460059641 100319475328460059641 No Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, 1144, Guilan, Iran H. Alaf Noveirian 100319475328460059640 100319475328460059640 No Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, 1144, Guilan, Iran