title: Combined effects of agricultural activity and parasites on biomarkers in the bullfrog, Rana catasbeiana.
abstract: Agricultural contaminants can have devastating impacts on amphibian survival and development, particularly considering their sensitivity to environmental perturbation. However, it is commonly overlooked that amphibians are infected with various parasites that can influence the overall health of the animal when exposed to a stressful environment. We investigated the interaction of agriculture and parasitism on the health of bullfrogs (Rana catesbeiana) in the field. Nine physiological and immunological biomarkers were related to naturally acquired parasite infections, along a gradient of agricultural activity. Most health biomarkers were affected by agriculture, parasitism, or both. Although bullfrogs residing in agricultural areas were infected with fewer parasite species, reflecting environmentally compromised ecosystems, certain persistent parasites interacted with agricultural disturbance to alter the physiology and immune competence of bullfrogs. The consequences of the combination for animal health highlight the importance of parasitism in ecotoxicological studies. Consideration of parasitism is warranted when evaluating the influence of anthropogenic disturbance on amphibian declines and environmental health.
authors.affiliation: Aquatic Ecosystem Protection Research Division, Water Science and Technology Directorate, Science and Technology Branch, St. Lawrence Centre, Environment Canada, 105 rue. McGill, 7th Floor, Montreal QCH2Y2E7, Canada. david.marcogliese@ec.gc.ca
authors.forename: David J
authors.initials: DJ
authors.lastname: Marcogliese
authors.forename: Kayla C
authors.initials: KC
authors.lastname: King
authors.forename: Harri M
authors.initials: HM
authors.lastname: Salo
authors.forename: Michel
authors.initials: M
authors.lastname: Fournier
authors.forename: Pauline
authors.initials: P
authors.lastname: Brousseau
authors.forename: Philip
authors.initials: P
authors.lastname: Spear
authors.forename: Louise
authors.initials: L
authors.lastname: Champoux
authors.forename: J Daniel
authors.initials: JD
authors.lastname: McLaughlin
authors.forename: Monique
authors.initials: M
authors.lastname: Boily
mesh_terms: D000383:Agriculture; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001772:Blood Cell Count; D004784:Environmental Monitoring; D006374:Helminthiasis, Animal / Q000097:blood / Q000469:parasitology*; D006376:Helminths / Q000502:physiology*; D011892:Rana catesbeiana / Q000378:metabolism* / Q000469:parasitology*; D014801:Vitamin A / Q000097:blood
chemical_list: D015415:Biomarkers; D014801:Vitamin A