Correspondence between mercury and stable isotopes in high Arctic marine and terrestrial avian species from northwest Greenland

• Published in: Polar biology Vol. 41; no. 7; pp. 1475 - 1491
• Main Authors: Burnham, Jennifer Horwath, Burnham, Kurt K., Chumchal, Matthew M., Welker, Jeffrey M., Johnson, Jeff A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2018; Springer; Springer Nature B.V
• Subjects: Air bases; Analysis; Arctic research; Auks; Bioindicators; Biomedical and Life Sciences; Biomonitoring; Birds; Blood; Breeding grounds; Breeding sites; Cepphus grylle; Ecological effects; Ecological monitoring; Ecology; Falco peregrinus; Food chains; Food chains (Ecology); Food contamination; Food webs; Freshwater; Indicator organisms; Indicator species; Indicators (Biology); Inland water environment; Isotopes; Life Sciences; Marine ecology; Mercury; Mercury (metal); Microbiology; Migratory species; Nesting; Oceanography; Original Paper; Plant Sciences; Prey; Seabirds; Small mammals; Stable isotopes; Toxicity; Uria lomvia; Wet weight; Zoology; Arctic region; Greenland; Seabird; Arctic; Contaminants; Mercury; Stable isotopes
• ISSN: 0722-4060; 1432-2056
• DOI: 10.1007/s00300-018-2302-9

Birds are useful bioindicators of environmental contamination around the globe, but avian studies in the high Arctic have been primarily limited to a few abundant species. This study was designed to assess mercury (Hg) concentrations in both abundant and less-abundant marine and terrestrial avian species on breeding grounds in northwest Greenland using blood sampling. Twenty-four migratory avian species ( n  = 625) were sampled over a three-year period (2010–2012) along 750 km of coastline near Thule Air Base (77° N, 68° W). Whole blood samples were analyzed for total Hg along with δ 13 C and δ 15 N to estimate food web position. A significant positive correlation was observed between mean Hg concentrations and trophic position, with adult mean Hg concentrations ranging from 11.4 to 1164 ng g −1 wet weight. Eleven species examined in this study had blood Hg concentrations suggestive of a low risk for Hg toxicity. Some Peregrine Falcon ( Falco peregrinus ), Thick-billed Murre ( Uria lomvia ), and Black Guillemot ( Cepphus grylle) individuals had concentrations of Hg suggestive of medium risk for Hg toxicity (Hg concentrations between 1000–3000 ng g −1 ww). Decreasing δ 15 N values in birds from the central study area suggest a nonuniform geographic pattern of increased freshwater influx and subsequent changes in prey availability, which correspond to lower avian Hg levels. This study provides strong evidence that marine and terrestrial feeding ecology of avian species in NW Greenland contributes to their mercury exposure; however, intraspecific variation in ecology and nesting locations in the region may influence those patterns.