© 2020 Elsevier LtdIn this study, heavy metals (Cd, Co, Cu, Ni, Pb, Zn, V) and 210Pb analyses have been performed in the marine biota (scaldfish, sea lettuce, crab). Samples were collected from 5 different parts of the Marmara Sea and Western Black Sea in January 2020. The results indicated that the highest Cu and Zn content was found in algae samples, but it was observed that heavy metal concentrations such as Co, Cu, Cd and V were generally low and under permissible limit. Also, 210Pb (radioactive isotope of Pb) activity levels were determined to vary from 23.20 Bq kg−1 to 52.67 Bq kg−1 dry weight. It was clearly seen that there was a linear correlation between the toxic and radioactive Pb when the obtained data were compared.