Biogeochemical interactions affecting hepatic trace element levels in aquatic birds

Abstract

Abstract-Knowledge of elemental interactions is important to the toxicological assessment of wildlife in the geochemical environment. This study determines the concentrations of Al, As, B, Ba, Be, Cd, Cr, Cu, Fe, Pb, Li, Mg, Mn, Hg, Mo, Ni, Se, Ag, V, and Zn in aquatic bird liver, fish liver, whole bivalves, insects, and waters in several aquatic ecosystems in northern California. There is evidence of strong in vivo and environmental interactions, including the observation of manganese as a possible cofactor or indicator in selenium bioaccumulation. The nearest neighbor selenium correlation in aquatic bird liver tissue that results from this work is Cd-Mn-Se-HgAs. The correlation of liver selenium to manganese in vivo and the result that the majority of the variance in liver selenium concentration is contained in the manganese term of the regression model relating Se to Cd, Mn, and Hg is new knowledge in the study of aquatic birds. A linear relationship between liver selenium and environmental manganese (water and sediment) is found in the data, suggesting a water chemistry compartmentalization or activation of toxicants. Alternatively, the hepatic concentrations of selenium, manganese, and iron suggest induction of enzymes in response to oxidative stress.

Organochlorine and trace element contamination in wintering and migrating diving ducks in the southern great lakes, USA, since the zebra mussel invasion

“…Trace elements are often correlated [57,58]. In contrast to the clustering among cadmium, manganese, selenium, mercury, and arsenic found in surf scoters ( Melanitta perspicil‐lata ) in San Francisco Bay [57] and between mercury and selenium in surf scoters and greater scaup ( Aythya marila ) [58] from San Francisco Bay, we found that cadmium correlated with only selenium and arsenic but not with mercury or manganese. Mercury did not correlate with any metal in livers of lesser scaup from western Lake Erie nor did mercury correlate with any other trace element in white‐winged scoters from Alaska [38].…”

“…These values were well below levels associated with zinc toxicosis (1,200 μg/g dry wt [56]). Copper was somewhat higher in livers of scaup from Lake Erie and Indiana Harbor (means 59.9 μg/g dry wt) than those of scaup from the Chesapeake Bay (mean 40 μg/g wt) but were lower than several other waterfowl species collected from Chesapeake Bay [43,48] and were within the normal range [57].…”

“…Mercury did not correlate with any metal in livers of lesser scaup from western Lake Erie nor did mercury correlate with any other trace element in white‐winged scoters from Alaska [38]. Although zinc correlated with magnesium in lesser scaup in western Lake Erie, the correlation was weaker (r 2 = 0.48) than Moller [57] found.…”

Mercury‐selenium association in antarctic seal hairs and animal excrements over the past 1,500 years

“…1), one explanation might be that the level of Hg is too high for the self‐protection mechanism. Additionally, it has been reported that Se also detoxifies other heavy metals [29,30,38–40], and toxic metals (e.g., Cd and Mn) and metalloid (e.g., As) may compete for binding with Se‐protein and weaken the correlation between Hg and Se. The exact cause, however, remains to be investigated further.…”