Bioaccumulation of heavy metals zinc, copper, and iron in the sediment, carapace, and muscle tissue of the crab Thalamita crenata (Rüppell, 1830) in the coasts of Chabahar Bay

The aim of this work was to investigate the accumulation of iron, zinc, and copper heavy metals in the sediments and muscle tissue and shell of the crab Thalamita crenata in Chabahar Bay from two stations of Tis and Konarak, by sampling 40 crab samples (male and female). Samples were collected in 2022 and transferred to the laboratory, after biometrics and sample preparation; the concentration of heavy metals was measured by an atomic absorption spectrometer. The results showed that the pattern of accumulation of heavy metals in the muscle tissue and shell is zinc>iron>copper. However, in the sediment, it was as iron>zinc>copper. The concentration of heavy metals in the muscle tissue was significantly higher than in the shell (P<0.05). Also, the concentration of heavy metals in the muscle tissue of females was significantly higher than that of males (except for iron in Tis station). There was no significant difference in the concentration of metals between males and females in the shell (P<0.05). The accumulation of heavy metals in crabs and sediments of Konarak station was higher than that of Tis station (except for iron in the muscle of Tis station). According to the results, there was a significant positive correlation between the accumulation of metals in the muscle tissue and crab shell, but no significant correlation was observed between the concentration of metals in the sediment and the tissue and shell. In the current study, the bioaccumulation results of heavy metals in sediment showed that the concentration of heavy metals in the sediment of Konarak station was higher than that of Tis station. The accumulation of heavy metals in crab organs depends on the physiological role of the organs. Based on the results, there was a difference between male and female crabs in terms of heavy metal accumulation that has been mainly attributed to differences in diet or differences in habitat. Comparing the concentration of metals in the muscle tissue of T. crenata of the study area with the international standards showed that the concentration of each metal, copper, is higher than the international standards, and iron is close to the WHO standard. Therefore, T. crenata crab of the studied area is dangerous for consumers in terms of copper and iron.