Survival rates and blood metal concentrations in two species of free‐ranging North American sea ducks

Abstract

Abstract-Populations of several species of North American sea ducks have declined in the past few decades. Exposure to environmental contaminants, particularly metals, has been proposed as one of many possible factors contributing to these declines. Population dynamics are influenced by survival rates and breeding effort. In the present study, we examined the relationships between blood metal concentrations (Cd, Pb, Se, and Hg) and apparent annual survival and recapture probabilities (the latter as a surrogate for breeding effort) in adult females of two sea duck species, the king eider (Somateria spectabilis) and the white-winged scoter (Melanitta fusca), both of which have experienced declines in continental population during in recent years. No support was found for the hypothesis that exposure of white-winged scoters to these metals or of king eiders to Cd, Se, and Pb adversely affected probabilities of apparent annual survival. We detected a weak negative relationship ( ϭ Ϫ0.833) between Hg and annual survival ␤ of king eiders, but the 90% confidence interval of the slope estimate overlapped zero (Ϫ2.439 to ϩ0.672). Recapture probabilities were unrelated to concentrations of Cd, Se, and Pb in either species. Evidence indicated that Hg concentrations affected recapture probability in white-winged scoters ( ϭ Ϫ194.77; 90% confidence interval, Ϫ203.770 to Ϫ185.778). Mercury levels were low ␤ in both species, and blood samples may not adequately represent long-term exposure to Hg. Therefore, conclusions regarding Hg effects on these birds should be considered with caution.

Survival rate and breeding outputs in a high Arctic seabird exposed to legacy persistent organic pollutants and mercury

“…The adult survival rate of kittiwakes was not jeopardized by Hg, which corroborates most of the previous studies in free-living birds (Wayland et al, 2008;Hallinger et al, 2011;Goutte et al, 2014a,b). Apparent survival rate was negatively linked to HCB levels in females, to mixture of chlordane and oxychlordane, and tended to be negatively correlated with P PCBs or DDE levels.…”

“…Apparent survival rate was lower in glaucous gulls Larus hyperboreus, bearing the highest levels of oxychlordane, a metabolite of the chlordane mixture, which is regarded as one of the most toxic POPs (Erikstad et al, 2013). However, adult survival rate was not related to POPs or Hg in tree swallows (Tachycineta bicolor), king eiders (Somateria spectabilis), white-winged scoters (Melanitta fusca), wandering albatrosses and two Catharacta skua species (Wayland et al, 2008;Hallinger et al, 2011;Goutte et al, 2014a,b).…”

Elevated mercury levels in a wintering population of common eiders ( Somateria mollissima ) in the northeastern United States

“…Declines in several of these species have led to increased research on the effects of environmental contaminants on their populations and physiology (Provencher et al, http://dx.doi.org/10.1016/j.marpolbul.2014.07.015 0025-326X/Ó 2014 Elsevier Ltd. All rights reserved. 2014; Wayland et al, 2008a;Fisk et al, 2005;Barjaktarovic et al, 2002). Trace elements in sea ducks have typically been examined in liver or kidney samples; however non-lethal sampling methods using feather and blood samples have recently been used with increased frequency (Bond and Diamond, 2009;Burger and Gochfeld, 2009;Wayland et al, 2007).…”

Examination of Eurasian Griffon Vultures (Gyps fulvus fulvus) in Israel for Exposure to Environmental Toxicants Using Dried Blood Spots

“…However, a specific investigation in 6 GV in Spain showed a greater mean of 110 ng/ml in whole blood (maximum value 200) (Garcia-Fernandez et al 1995). No known toxicity threshold exists for Cd in the blood of birds (Wayland et al 2008b). Therefore, the Cd levels\10 ng/ml in the GV in this study appear to be lower than levels of expected detrimental effects.…”

“…No commonly accepted toxicity threshold exists for Hg in the blood of birds (Wayland et al 2008b). In man, Hg concentrations in whole blood between 20 and 100 ng/ml have been determined by health officials to be at ''increasing risk'' (AMAP 2009).…”