influence of breeding colony and sex on mercury, selenium and lead levels and carbon and nitrogen stable isotope signatures in summer and winter feathers of Calonectris shearwaters

• Published in: Oecologia Vol. 159; no. 2; pp. 345 - 354
• Main Authors: Ramos, Raül, González-Solís, Jacob, Forero, Manuela G, Moreno, Rocío, Gómez-Díaz, Elena, Ruiz, Xavier, Hobson, Keith A
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.03.2009; Springer; Springer-Verlag; Springer Nature B.V
• Subjects: Animal, plant and microbial ecology; Animals; Anthropogenic factors; Applied ecology; Aquatic birds; Archipelagoes; Aves; Aviculture; Biological and medical sciences; Biomedical and Life Sciences; Birds - metabolism; Birds - physiology; Breeding; Breeding seasons; Canaries; Carbon Isotopes - metabolism; Contaminants; Decontamination; Ecology; Ecosystem Ecology - Original Paper; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Environmental perception; Environmental pollution; Feathers; Feathers - metabolism; Female; Food Chain; Fundamental and applied biological sciences. Psychology; Hydrology/Water Resources; Isotopes; Lead; Lead - metabolism; Life Sciences; Male; Marine and brackish environment; Marine ecology; Marine ecosystems; Marine pollution; Mercury; Mercury - metabolism; Migratory species; Nitrogen Isotopes - metabolism; Ocean pollution; Plant Sciences; Pollution levels; Sea birds; Seasons; Selenium; Selenium - metabolism; Spatial analysis; Species Specificity; Stable isotopes; Water Pollutants, Chemical - metabolism; Winter; Sealife contamination; Carbon-13; Nitrogen-15; Marine foodweb pollutants; Migratory connectivity; Isotope labelling; Sex; Nitrogen; Carbon; Contamination; Heavy metal; Marine environment; Pollutant; Vertebrata; Reproduction; Food web; Migratory; Lead; Colony; Feather; Selenium; Aves; Mercury
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-008-1215-7

Contamination in marine foodwebs is nowadays of great environmental concern owing to the increasing levels of pollution in marine ecosystems from different anthropogenic sources. Seabirds can be used as indicators of regional contaminant patterns across large temporal and spatial scales. We analysed Hg, Se and Pb levels as well as stable isotope ratios of C (¹³C/¹²C, δ¹³C) and N (¹⁵N/¹⁴N, δ¹⁵N) in breeding- and winter-season feathers on males and females of two related shearwater species, providing information on spatiotemporal patterns of contaminants as well as the influence of the trophic ecology of these seabirds on contaminant levels. During the breeding season, Se and Pb concentrations were highest at the Cape Verde archipelago, showing no differences among the other colonies or between the sexes. However, Hg levels varied among colonies, being highest in the Mediterranean, probably resulting from the larger emissions and fallout of this pollutant in Europe. Feathers grown during breeding also showed sexual differences in Hg concentrations and δ¹³C. Differences in Hg concentration between sexes are mainly due to egg-laying decontamination in females. In contrast, differences in Hg among colonies are probably related to differences in trophic ecology, as indicated by δ¹³C and δ¹⁵N measurements. Contaminant concentrations in winter-grown feathers did not show any relationship with stable isotope values but were affected by contaminant loads associated with the breeding season. These findings suggest that the interpretation of contaminant levels of migratory species from feathers moulted out of the breeding season should be made with caution because those values could reflect exposures to contaminants acquired during the breeding season. We conclude that factors other than feeding ecology may play an important role in the interpretation of contaminant levels and their annual dynamics at several spatial scales. Consideration of the relevant temporal context provided by isotopic signatures and contaminant concentrations is important in deciphering contaminant information based on various tissues.