Exposure of black-necked grebes (Podiceps nigricollis) to metal pollution during the moulting period in the Odiel Marshes, Southwest Spain

• Published in: Chemosphere (Oxford) Vol. 216; pp. 774 - 784
• Main Authors: Rodríguez-Estival, Jaime, Sánchez, Marta I., Ramo, Cristina, Varo, Nico, Amat, Juan A., Garrido-Fernández, Juan, Hornero-Méndez, Dámaso, Ortiz-Santaliestra, Manuel E., Taggart, Mark A., Martinez-Haro, Mónica, Green, Andy J., Mateo, Rafael
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2019
• Subjects: Animals; Artemia; Birds; Body condition; Carotenoids; Environmental Monitoring; Environmental Pollution; Eye redness; Metal pollution; Metals - adverse effects; Metals - chemistry; Molting; Spain; Waterbirds; Wetlands; Spain; Waterbirds; Carotenoids; Artemia; Eye redness; Body condition; Metal pollution
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.10.145

European populations of black-necked grebes (Podiceps nigricollis) congregate every year to moult at the salt ponds of the Odiel Marshes (SW Spain). However, the Odiel Marshes are part of one of the most metal-polluted coastal estuaries in the world, which may pose risks to wildlife. We assessed the exposure of grebes to metal pollution during the critical moulting period in the Odiel Marshes and its potential to cause adverse health effects. Levels of metals in red blood pellet (as a biomarker of exposure), plasma carotenoids, eye redness, and body condition (as biomarkers of effects) were studied. Metal content was also analyzed in the brine shrimp Artemia parthenogenetica, the most important food for grebes in this hypersaline ecosystem during the moulting period. Results showed that, in comparison to toxicity thresholds, grebes had relatively high blood levels of arsenic (As), mercury (Hg) and zinc (Zn). The high loads found in Artemia and the way blood levels vary during the moulting period indicate that shrimp consumption may be the main route of metal exposure for grebes. Plasma carotenoids and body condition showed a positive association with exposure to As, while the relationship of lutein-like carotenoids with Hg accumulation was negative at the beginning of the moulting period to become positive afterwards. Moreover, eye redness was negatively affected by As accumulation. Factors including food resource availability, seasonal fluctuations in physiological status, and interannual variations in the degree of environmental contamination should be considered in monitoring efforts when using moult migrant waterbirds as sentinel species. [Display omitted] •Moult migrant grebe was used as sentinel of metal pollution in the Odiel Marshes.•Grebes had high blood levels of As, Hg and Zn in comparison to toxicity thresholds.•Metals in Artemia and temporal changes in exposure suggest a food chain transfer.•Plasma carotenoids, eye redness and body condition were influenced by metal exposure.