Foraging in marine habitats increases mercury concentrations in a generalist seabird.

Autor: Clatterbuck CA; San Diego State University, Biology Department, San Diego, CA, USA. Electronic address: cclatterbuck@ucdavis.edu., Lewison RL; San Diego State University, Biology Department, San Diego, CA, USA., Orben RA; Oregon State University, Department of Fisheries and Wildlife, Hatfield Marine Science Center, Newport, OR, USA., Ackerman JT; U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, CA, USA., Torres LG; Oregon State University, Department of Fisheries and Wildlife, Marine Mammal Institute, Hatfield Marine Science Center, Newport, OR, USA., Suryan RM; Oregon State University, Department of Fisheries and Wildlife, Hatfield Marine Science Center, Newport, OR, USA., Warzybok P; Point Blue Conservation Science, Petaluma, CA, USA., Jahncke J; Point Blue Conservation Science, Petaluma, CA, USA., Shaffer SA; San José State University, Department of Biological Sciences, San Jose, CA, USA.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2021 Sep; Vol. 279, pp. 130470. Date of Electronic Publication: 2021 Apr 12.
DOI: 10.1016/j.chemosphere.2021.130470
Abstrakt: Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine, estuarine, or terrestrial food webs. The ecological impacts of differential foraging may be especially important for generalist species that exhibit high plasticity in foraging habitats, locations, or diet. Here, we investigate whether foraging habitat, sex, or fidelity to a foraging area impact blood mercury concentrations in western gulls (Larus occidentalis) from three colonies on the US west coast. Cluster analyses showed that nearly 70% of western gulls foraged primarily in ocean or coastal habitats, whereas the remaining gulls foraged in terrestrial and freshwater habitats. Gulls that foraged in ocean or coastal habitats for half or more of their foraging locations had 55% higher mercury concentrations than gulls that forage in freshwater and terrestrial habitats. Ocean-foraging gulls also had lower fidelity to a specific foraging area than freshwater and terrestrial-foraging gulls, but fidelity and sex were unrelated to gull blood mercury concentrations in all models. These findings support existing research that has described elevated mercury levels in species using aquatic habitats. Our analyses also demonstrate that gulls can be used to detect differences in contaminant exposure over broad geographic scales and across coarse habitat types, a factor that may influence gull health and persistence of other populations that forage across the land-sea gradient.
(Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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