Mercury, Lead, Cadmium, Cobalt, Arsenic and Selenium in the Blood of Semipalmated Sandpipers (Calidris pusilla) from Suriname, South America: Age-related Differences in Wintering Site and Comparisons with a Stopover Site in New Jersey, USA.

Joanna Burger,David Mizrahi,Christian Jeitner,Nellie Tsipoura,Michael Gochfeld

doi:10.3390/toxics6020027

Abstract

It is essential to understand contaminant exposure and to compare levels of contaminants in organisms at different ages to determine if there is bioaccumulation, and to compare levels encountered in different geographical areas. In this paper, we report levels of mercury, lead, cadmium, cobalt, arsenic and selenium in the blood of semipalmated sandpipers (Calidris pusilla) wintering in Suriname as a function of age, and compare them to blood levels in northbound migrants at a stopover in Delaware Bay, New Jersey. We found (1) young birds had higher levels of cadmium, cobalt, and lead than adults (after second year birds); (2) there were no age-related differences for arsenic, mercury and selenium; (3) only four of the possible 16 inter-metal correlations were significant, at the 0.05 level; (4) the highest correlation was between cadmium and lead (Kendall tau = 0.37); and (5) the adult sandpipers had significantly higher levels of cadmium, mercury and selenium in Suriname than in New Jersey, while the New Jersey birds had significantly higher levels of arsenic. Suriname samples were obtained in April, after both age classes had spent the winter in Suriname, which suggests that sandpipers are accumulating higher levels of trace elements in Suriname than in Delaware Bay. The levels of selenium may be within a range of concern for adverse effects, but little is known about adverse effect levels of trace elements in the blood of wild birds.

Highlights

Environmental scientists, managers, public policy makers, and the public are interested in whether humans and other animals are exposed to increasing levels of contaminants world-wide, especially in developing countries and in remote areas
Since 2009, approximately 500 semipalmated sandpipers have been captured each winter along the coast of Suriname, and since the mid-90s, more than 25,000 individuals of the species have been captured as part of an international effort to understand the biology, ecology, and migratory behavior of shorebirds in Delaware Bay
Selenium and mercury levels showed no consistent patterns in the blood of the shorebirds we examined from Suriname and Delaware Bay

Summary

Introduction

Environmental scientists, managers, public policy makers, and the public are interested in whether humans and other animals are exposed to increasing levels of contaminants world-wide, especially in developing countries and in remote areas. It is essential to select bioindicators of environmental contamination that provide as much information as possible about global levels, temporal trends, and spatial trends. Feather concentrations reflect circulation levels when the feather was growing, which integrates exposure over a period of weeks, and information on molt patterns is essential. Blood levels reflect exposure at the time of collection, and relate directly to levels in other tissues [5,6]. For this reason, and because it can be collected from birds, blood is ideal for local monitoring [6]

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Discussion

Conclusion