Evaluate and Compare the Accumulation of the Heavy Metals in Tissues of the Gray Mullet (Liza aurata) during the Sexual Maturity and Sexual Rest

This study was conducted to measure the concentration of five heavy metals, including lead, cadmium, mercury, arsenic, and chrome in muscle liver, and gill of the gray mullet, Liza aurata in southern part of the Caspian Sea. The samples were collected from 100 adult gray mullet in 10 stations during the sexual maturity (in the fall) and sexual rest (in the spring). The muscle, liver, and gill tissues of each fish were separated in order to measure the concentration of the heavy metals. The acid digestion method was used to extract the metals from the tissues. The concentration was determined using a graphite furnace atomic absorption spectrometer. The mean concentration of lead, cadmium, mercury, arsenic, and chrome in the muscle tissue respectively was 1.40, 0.43, 0.16, 0.07 and 0.54 µg/g during the sexual maturity and 1.90, 0.93, 0.24, 0.12 and 0.61 µg/g during the sexual rest. Generally, the uptake of heavy metals during the sexual rest (Pb>Cd>Cr>Hg>As) was higher than that during the sexual maturity (Pb>Cr>Cd>Hg>As). The concentration of the metals in the three tissues was as follows: liver > gill > muscle. The difference between tissues in terms of the concentration of the metals was significant. The comparison of the data obtained for the muscle tissue with the standards of the World Health Organization and Australian National Health and Medical Research Council showed that the concentration of all the five heavy metals (Pb, Cr, Cd, Hg, As) was higher than the global standard level, and thus, the consumption of this fish can harm people.