Effects of Heavy Metals Pollution on Some Fish and Mollusc Species from Port Sudan, Sudan

Abstract

The effects on fishes Lethrinus harak and Cephalopholis minata and on the mollusc Tridacna maxima exposed to different concentrations of heavy metals vanadium, nickel, and copper were investigated. The study indicated that the LC50 for nickel were 198.200 ppm, for L. harak, 196.041 ppm for C. minata and 198.200 ppm for T. maxima. The LC50 for copper were 197.175 ppm for L. harak, 272.932 ppm for C. minata and 272.841 ppm in T. maxima. However, LC50 for vanadium recorded 131.836 ppm for L. harak, 164.769 ppm for C. minata and 164.037 ppm for T. maxima. On the other hand, LT50 due to nickel exposure recorded 74.815, 47.963, and 95.116 hours, for L. harak, C. minata and T. maxima, respectively. LT50 due to copper recorded 35.041, 47.681, and 71.835 hours for L. harak, C. minata and T. maxima, respectively. However, LT50 for vanadium were 11.989, 47.511 and 5.792 hours for L. harak, C. minata and T. maxima, respectively. In this study no response was detected in lower concentrations of nickel and copper i.e. 4 ppm and 32 ppm, however a high response was detected with the same concentrations of vanadium. The study indicated that T. maxima, was more tolerant for heavy metals pollution than L. harak and C. minata. Nickel concentrations detected in tissues analysis were 0.561-0.04 ppm, 0.421-0.02 ppm and 0.871-0.03 ppm for L. harak, C. minata and T. maxima, respectively. While copper concentrations recorded 1.1030-0.09 ppm, 0.4060-0.02 ppm and 1.35-0.03 ppm for L. harak, C. minata and T. maxima, respectively. However, vanadium concentrations, recorded 0.010-0.00 ppm, 0.04-0.014-0.01 ppm and 0.042-0.00 ppm for L. harak, C. minata, and T. maxima, respectively.