title: Mercury in parasitic nematodes and trematodes and their double-crested cormorant hosts: bioaccumulation in the face of sequestration by nematodes.
abstract: Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values (δ(15)N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. δ(13)C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.
authors.affiliation: Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada. srobinsc@connect.carleton.ca
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Robinson
authors.forename: Mark R
authors.initials: MR
authors.lastname: Forbes
authors.forename: Craig E
authors.initials: CE
authors.lastname: Hebert
mesh_terms: D000818:Animals; D001199:Ascaridoidea / Q000378:metabolism* / Q000472:pathogenicity; D001717:Birds / Q000378:metabolism* / Q000469:parasitology; D002247:Carbon Isotopes / Q000378:metabolism; D004032:Diet; D004450:Echinostomatidae / Q000378:metabolism* / Q000472:pathogenicity; D005260:Female; D020387:Food Chain; D006790:Host-Parasite Interactions; D008297:Male; D008628:Mercury / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000378:metabolism; D012737:Sex Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D008628:Mercury