Comparison of mercury bioaccumulation in eel (Anguilla anguilla) and roach (Rutilus rutilus) from river systems in East Anglia, UK -: I.: Concentrations in fish tissue

Concentrations of total mercury (T-Hg) were measured in eel and roach from five selected rivers in East Anglia, U.K, to determine Hg bioaccumulation in fish throughout the region. Levels of T-Hg in sediment and river water were also analysed to assess their potential as pathways to the fish. Accumulated Hg levels in River Yare eel and roach continue to exhibit a strong positive relationship with surface sediment Hg levels, which are declining with time. Mercury in muscle from all sampled fish were below the limit set by the EU Directive (93/351/EEC). Analysis of muscle:liver (M:L) ratios confirm that eel from all sites are in equilibrium with their environment. Various statistical methods (single factor analysis of variance, Spearman's correlation coefficients) were performed on the experimentally derived data on mercury concentrations in fish flesh. Significant correlations were noted for accumulated Hg in fish flesh with length and weight in eel, and length, weight and age in roach.