Miebaka Moslen, Ikem KE Ekweozor and Nsirim-Dimkpa Nwoka
The aim of this study was to assess accumulation of heavy metals in tissues of Periwinkle (Tympanotonus fuscatus var radula (L.)) obtained from Azuabie creek using Okujagu creek as control location. Fifty samples were collected from each site for three months (October-December 2015). Atomic Absorption Spectrophotometric technique was used in heavy metal analysis. Mean metal concentrations in sediments were as follows Zn: 178.08 mgkg-1; Cd: 0.3 mgkg-1; Cr: 14.27 mgkg-1 and Pb: 18.75 mgkg-1. While those in Periwinkle tissue with biosediment accumulation factor (BAF) in parenthesis were thus Zn: 24.42 mgkg-1 (0.137); Cd: 0.02 mgkg-1 (0.067); Cr: 1.57 mgkg-1 (0.11) and Pb 0.01 mgkg-1 0.001). The result of BAF of metals indicated low values which could be related to assimilation and excretion rate of heavy metals in the organisms examined. Variations in the concentration of Zn in the gastropod tissues showed significant difference (p<0.01) between sites, likewise, Cr (p<0.001) and Cd (p<0.05). In conclusion, comparison between the two creeks showed that tissue samples from St1, St2 and St3 (Azuabie creek) had higher concentration of metals in relation to the control station (Okujagu creek) indicating potentials for accumulation, mainly due to differences in anthropogenic activities. Cr, Cd and Pb concentrations in tissue had mean values less than the recommended limits in seafood by FAO/WHO however, regular monitoring is required to observe perturbations.
