Toxic Metals in Pilot Whales (Globicephala melaena) from Standings in 1986 and 1990 on Cape Cod, Massachusetts

Abstract

Concentrations of As, Cd, Cu, Hg, Pb, and Se were measured in 17 adult and 8 fetal pilot whales (Globicephala melaena). Total Hg and Se both occurred in very high concentrations in liver and kidney and in liver were significantly correlated with animal length (and each other) which indicates bioaccumulation over time. Methyl mercury, as a percentage of total Hg, varied inversely with total Hg indicating demethylation was occurring; a one-to-one molar association of Hg and Se was found which is believed to provide protection against Hg toxicity. Arsenic concentrations were relatively low, but Cd concentrations were consistently very high in adult kidney. Lead in adult liver was also correlated with animal length indicating long term bioaccumulation. All non-essential elements were found in critical fetal tissues which indicates maternal transfer occurred. Cadmium in fetal kidney was over 30 times higher than either brain or liver, indicating early differential accumulation and supporting maternal transfer. Matched pairs of mother and fetus liver indicated no correlation of elements, which may due to the temporal nature of bioaccumulation and the immobility of some elements. These results were compared to other mammalian studies to evaluate the toxicological implications of observed tissue concentrations.