Citation: Erikstad, K. E., H. Sandvik, T. K. Reiertsen, J. O. Bustnes, and H. Strøm (2013) Persistent organic pollution in a high-Arctic top predator: sex-dependent thresholds in adult survival. Proceedings of the Royal Society. B, Biological Sciences, 280, 20131483, 7 pp.
doi: 10.1098/rspb.2013.1483 [what’s a doi?].
Key words: Bjørnøya, capture–mark–recapture, Larus hyperboreus, organochlorine contamination, oxychlordane, survival threshold.
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.
Firstly, at some threshold of OC concentration, parents (especially males)
may abandon reproduction to maximize their own survival. Secondly,
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.
Full text: © 2013 The authors. If you accept (i) that further reproduction, and all further use other than for personal research, is subject to permission from the publisher (Royal Society), and (ii) that printouts have to be made on recycled paper, you may download the article here (pdf, 0.6 MB).
Supplementary material: Individual input data and population viability analyses are available from the Dryad Digital Repository at doi:10.5061/dryad.pm885 [what’s Dryad?].