Assessment of Heavy Metal Concentrations in the Gut and Muscle Tissues of Swimming Crabs (Callinectes amnicola) from Rumuolumeni Creek, Rivers State, Nigeria

Abstract

The aim of this study was to assess heavy metals concentration in the gut and muscles of swimming crab (Callinectes amnicola). Four sampling stations were established, samples was collected from each, for a period of three months. Heavy metals investigated were Zn, Pb, Cu and Ni, the part of crab involved was gut and muscles, they were oven dried and Atomic Absorption Spectrophotometer (AAS) model AA320N, was used to analyze the concentration of heavy metals. Analysis of variance was used to calculate mean and standard deviation while statistical significance was assessed at 0.05 probability levels using Turkey tests. Heavy metals concentration results in the gut of Callinectes amnicola for the period of three months showed the following Zn 8.31±2.33 to 9.69±2.72, Pb 0.19±0.15 to 0.56±0.46, Cu 71.14±17.49 to 89.53±22.01, Ni 0.02±0.01 to 0.05±0.03 while muscles were Zn 2.70±0.76  to 3.15±0.88, Pb 0.42±0.35 to 0.45±0.37, Cu 55.49±13.64 to 58.30±14.33, Ni 0.02±0.01 to 0.02±0.01. The available results were compared with standard limit of World Health Organization (2003).  In the gut of C. amnicola  Pb and  Cu was above permissible limit of WHO, while in muscles only Cu was above the permissible limit of WHO,  which shows  more accumulation of heavy metals in the  gut than  the muscles. Since there are accumulations of heavy metals above permissible limits of WHO both in crab gut and muscles, as such its consumption poses health risk to consumers. It is recommended that people consuming crabs in Rumuolumeni Creek should do it with caution.