title: Accumulation properties of inorganic mercury and organic mercury in the red-crowned crane Grus japonensis in east Hokkaido, Japan.
abstract: The red-crowned (Japanese) crane Grus japonensis is native to east Hokkaido, Japan, in contrast to the East Asia mainland. Previously, we reported that red-crowned cranes in Hokkaido were highly contaminated with mercury in the 1990s and that the contamination rapidly decreased to a moderate level in the 2000s. In the present study, we determined levels of organic mercury (O-Hg) in the liver and kidney of cranes in east Hokkaido in comparison with levels of total mercury (T-Hg). T-Hg levels in the kidneys were higher than those in the livers in adults but not in subadults and juveniles; however, the reverse was the case for O-Hg even for adults. The ratio of O-Hg to T-Hg in both the liver and kidney decreased as T-Hg increased in the three developmental stages. While the ratios of O-Hg to T-Hg in the liver and kidney of adults were significantly lower than those of juveniles, the ratios were similar for adults and juveniles in a lower range of T-Hg. The ratio of selenium (Se) to T-Hg decreased as T-Hg increased in both the liver and kidney, irrespective of stages. Mercury burdens in feathers were about 59% and 67% of the total body burdens for juveniles and adults, respectively. Furthermore, ratios of carbon and nitrogen stable isotopes to T-Hg varied greatly, with no relation to mercury level in the liver. The results suggest slow accumulation of inorganic mercury in the kidney of red-crowned cranes in east Hokkaido, Japan.
authors.affiliation: School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan. Electronic address: hteraoka@rakuno.ac.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Teraoka
authors.affiliation: School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan. Electronic address: tomato.erika@gmail.com.
authors.forename: Erika
authors.initials: E
authors.lastname: Okamoto
authors.affiliation: School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan. Electronic address: gonta_x0gonsuke@yahoo.co.jp.
authors.forename: Moe
authors.initials: M
authors.lastname: Kudo
authors.affiliation: Laboratory of Toxicology, Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan. Electronic address: shouta-nakayama@vetmed.hokudai.ac.jp.
authors.forename: Shouta M M
authors.initials: SM
authors.lastname: Nakayama
authors.affiliation: Laboratory of Toxicology, Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa. Electronic address: y_ikenaka@vetmed.hokudai.ac.jp.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ikenaka
authors.affiliation: Laboratory of Toxicology, Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan. Electronic address: ishizum@vetmed.hokudai.ac.jp.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ishizuka
authors.affiliation: School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293, Japan. Electronic address: endotty@hoku-iryo-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Endo
authors.affiliation: School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan. Electronic address: tko-kita@rakuno.ac.jp.
authors.forename: Takio
authors.initials: T
authors.lastname: Kitazawa
authors.affiliation: School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan. Electronic address: hiraga@rakuno.ac.jp.
authors.forename: Takeo
authors.initials: T
authors.lastname: Hiraga
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001717:Birds / Q000254:growth & development / Q000378:metabolism*; D001822:Body Burden; D004785:Environmental Pollutants / Q000032:analysis / Q000493:pharmacokinetics*; D005241:Feathers / Q000737:chemistry; D007564:Japan; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008628:Mercury / Q000032:analysis / Q000493:pharmacokinetics*; D009941:Organomercury Compounds / Q000032:analysis / Q000493:pharmacokinetics*; D012643:Selenium / Q000032:analysis / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D004785:Environmental Pollutants; D009941:Organomercury Compounds; D008628:Mercury; D012643:Selenium
keywords: Bird; Mercury; Metabolism