Persistent organic pollution in a high-Arctic top predator: sex-dependent thresholds in adult survival

Abstract

In long-lived species, any negative effect of pollution on adult survival may pose serious hazards to breeding populations. In this study, we measured concentrations of various organochlorines (OCs) (polychlorinated biphenyl and OC pesticides) in the blood of a large number of adult glaucous gulls (Larus hyperboreus) breeding on Bjørnøya (Bear Island) in the Norwegian Arctic, and modelled their local survival using capture-recapture analysis. Survival was negatively associated with concentrations of OCs in the blood. The effect of OCs was nonlinear and evident only among birds with the highest concentrations (the uppermost deciles of contamination). The threshold for depressed survival differed between the sexes, with females being more sensitive to contamination. For birds with lower OC concentration, survival was very high, i.e. at the upper range of survival rates reported from glaucous and other large gull species in other, presumably less contaminated populations. We propose two non-exclusive explanations. First, at some threshold of OC concentration, parents (especially males) may abandon reproduction to maximize their own survival. Second, high contamination of OC may eliminate the most sensitive individuals from the population (especially among females), inducing a strong selection towards high-quality and less sensitive phenotypes.

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

“…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. Only one study (Erikstad et al, 2013) highlighted a negative effect of oxychlordane on adult survival rate in the glaucous gull breeding in the Bjørnøya Island (blood levels of oxychlordane: 1.3e128.8 ng.g À1 wet weight, median: 13.2 ng.g À1 ww) and this effect was the most pronounced among the most contaminated females. Even if kittiwakes were more than 10-time less contaminated than glaucous gull (blood Table 5 Modeling the effects of S PCBs, p,p 0 -DDE, HCB and CHL levels and sex on demographic parameters of Rissa tridactyla (N ¼ 138).…”

“…Hg or POP levels were negatively related to long-term breeding probability and success in the wandering albatross Diomedea exulans and in two Catharacta skua species (Goutte et al, 2014a,b). 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).…”

“…This study aims at detecting whether breeding probability the year of sampling and demographic traits the following year (apparent adult survival rate, breeding probability, probability of successfully raising at least one chick and probability of successfully raising two chicks) were correlated with individual blood levels of Hg or POPs. According to the few available long-term studies on polar seabird species (Erikstad et al, 2013;Goutte et al, 2014a,b), we predicted deleterious effects of Hg or POPs on breeding probability and breeding success during the year of sampling and during the following year and deleterious effects of the chlordane mixture and metabolites on survival rate in black legged kittiwakes.…”

Demographic consequences of heavy metals and persistent organic pollutants in a vulnerable long-lived bird, the wandering albatross

“…In two Catharacta skua species, breeding failure in the following year, but not adult survival rate, was positively related to Hg exposure [10], as highlighted by the use of long-term datasets and multi-state mark-recapture models (MSMR [11]). Concerning POPs, very high concentrations of organochlorine compounds were related to increased mortality in the glaucous gull Larus hyperboreus [12], but their effects on long-term fecundity were not explored in that study.…”

“…The effects of Hg and Cd in red blood cells and S POPs in plasma on apparent probabilities of adult survival, return to the breeding colony, breeding, hatching and fledgling, were investigated by using a MSMR approach. According to recent studies on long-lived seabirds [10,12], a deleterious effect of Hg was expected on long-term breeding performances and a possible lethal effect of POPs was expected in the most contaminated wandering albatrosses. Then, population-level responses to an increase in Hg and POPs levels were assessed by establishing a life cycle for the wandering albatross and by including Hg-or POP-dependent demographic traits in the matrix population models [13].…”