Comparison on accumulation of heavy metals (Fe, Zn, Cu, Mn, and Ni) in soft and hard tissue of Blue Swimmer Crab (Portunus pelagicus) in Bushehr coastal

The dangers of bio-accumulation of metals at higher levels in the food chain are one of the major concerns in human health. Heavy metals are resistant to degradation and accumulate in the body of aquatic animals, including crayfish.
This study was conducted to compare the accumulation of heavy metals in soft and hard crab blue swimmers of Bushehr shores. Crab samples (40) were collected randomly in the autumn of 1395 using boats and fishing trips from Bushehr coastlines. The acid digestion method was used to prepare the samples. The concentrations of Fe, Zn, Cu, Mn, and Ni in hard tissue were 90.70±43.01, 52.93±6.78, 37.73±13.85, 23.50±7.76 and 4.37±3.66 mg/kg dry weight respectively and in soft tissue were 83.81±56.94, 17.51±4.11, 92.28±28.69, 69.12±3.73 and 4.24±3.90 respectively. Metal concentrations of hard tissue were significantly higher than those in soft tissue. Based on the results in soft crab tissue, the mean concentration of copper was higher than the WHO and NHMRC standards, the mean concentration of nickel was higher than the WHO and FAO standards and the mean concentration of zinc were lower than the global standard. In the hard tissue, the mean value of copper and nickel was higher than the international standards and Zn lower than these standards. Generally, Ni and Cu were higher than the standards that can create risk to human health.