The Effects of Lead, Cadmium, Mercury and Arsenic on Fish and Seawater in Red Sea and the Gulf of Aden at Three Different Locations in Yemen

Abstract

This study investigates concentrations of heavy metals (Pb, Cd, Hg and As) in water and muscle fish collected from three different sites (Aden, Al-Hodeidah and AL-Mukalla) of the Red Sea and the Gulf of Aden in Yemen�s coastal. Fresh samples were purchased from near the sea public auction site locations. The four species of fish (emperor) Lethrinus mahsena, (Longtail tuna) Thunnus tonggol, (Pickhandle Barracuda) Sphyraena jello and (Areolate grouper) Epinephelus areolatus were collected and analyzed, 81 samples of Seawater and 108 samples of muscle Fish were digested using suitable procedures. The heavy metal concentrations in the samples were measured using the Atomic Absorption Spectrophotometer. The obtained results showed that the concentration (mg/l) of the heavy metal in seawater (Pb-0.061�0.005, Cd-0.007�0.001, Hg-0.007�0.0005 and As-0.008�0.0003) was lower than that of the concentration (�g/g) of heavy metal in muscle (Pb0.101�0.012, Cd-0.046�0.010, Hg-0.058�0.002 and As-0.089�0.002). The results showed that, the heavy metals concentrations were high in stations AL- Hudaydah and AL- Mukalla and low in station of Aden. The highest mean concentration of Pb, Cd and As a in the muscles of the four studied fish species was 0.137� 0.014 and 0.069�0.021�g/g dry wt in large Epinephelus areolatus ; 0.106�0.007�g/g dry wt in large Lethrinus mahsena At Site AL- Hudaydah in Summer. The highest mean concentration of Hg a in the muscles of the four studied fish species was 0.071�0.012�g/g dry wt in large Epinephelus areolatus At Site Aden in summer. Positive relationships were found between metal levels and fish size. The results were analyzed and tested for differences between group means of stations and seasons for significance (P?0.05) using the analysis of variance one way ANOVA and two ways ANOVA technique. The obtained results showed that the heavy metals concentrations were significantly higher, during the summer season for seawater and muscle fish samples in all stations during the study period. From these results, we conclude that the heavy metals (Pb, Cd, Hg and As) in the muscles of fish and seawater, at Yemen�s coastal were still in range scale of international pollution standard However, the study recommends continuing the study of these pollutants and other contaminants and their impact on the environment and marine life.