title: Dietary and waterborne mercury accumulation by yellow perch: a field experiment.
abstract: It is well accepted that the majority of monomethylmercury (MMHg) in fish originates in their food; however, the additional contribution of water as a source to fish MMHg levels remains unclear. We used isotope enriched mercury (Hg) in a controlled field experiment to quantify the uptake of Hg from ingested and aqueous sources by young-of-year yellow perch (Perca flavescens). Water and zooplankton from a lake that had received (202)Hg-enriched additions (called spike Hg) for 7 y during a whole-ecosystem loading study (METAALICUS) provided natural, low-level Hg exposure. We achieved separation of exposure pathways by housing perch in one of four treatments: clean water + clean food; clean water + Hg spiked food; Hg spiked water + clean food; Hg spiked water + Hg spiked food. Fish accumulated MMHg directly from water, and this source accounted for at least 10% of MMHg in fish during the 27-d trial. Accumulation of spike Hg from water and food was additive, with food providing the majority of spike MMHg taken in by fish. Predictions from a bioenergetics model that excludes water as a source underestimated Hg in perch by 11%. This study illustrates the importance of acknowledging both food and water as sources of Hg to fish and suggests that aqueous Hg should be included as a source of contamination in bioaccumulation models and experiments.
authors: Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2.
authors: Lee E
authors: LE
authors: Hrenchuk
authors: Paul J
authors: PJ
authors: Blanchfield
authors: Michael J
authors: MJ
authors: Paterson
authors: Holger H
authors: HH
authors: Hintelmann
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004032:Diet; D004784:Environmental Monitoring; D005502:Food; D060106:Lakes / Q000737:chemistry; D008628:Mercury / Q000378:metabolism*; D008629:Mercury Isotopes; D008767:Methylmercury Compounds; D008954:Models, Biological; D009864:Ontario; D010471:Perches / Q000254:growth & development / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D008629:Mercury Isotopes; D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury