Examination of bioaccumulation and biomagnification of metals in a precambrian shield lake

Abstract

This paper reports on a comprehensive examination of metal levels at various trophic levels within an undisturbed Precambrian shield lake ecosystem. Concentrations of 21 naturally occurring elements (Hg, Cu, Al, Ba, S, Ni, Cd, Ca, Be, Zn, P, Pb, Mg, Sr, Fe, V, Mo, Mn, Ti, B, Cc) were measured in sediments, clams, fish, birds and mammals. Mercury was the only element to exhibit biomagnification in both aquatic and terrestial food chains. The levels of several metals were elevated in fish-eating birds relative to concentrations observed in the fish. Mercury was the only metal which accumulated in muscle tissue with increased age and size of all fish species tested. The concentrations of a few other metals were correlated to fish length, but these relationships were not consistent between species.