Persistent organic pollutants in red-crowned cranes (Grus japonensis) from Hokkaido, Japan

•Persistent organohalogen compounds accumulated in red-crowned cranes of Hokkaido.•Polychlorinated biphenyls were the most abundant contaminants.•The concentrations of organohalogen compounds were positively correlated.•Crane specimens exhibited a high enantiomeric excess of (+)-alpha-HCH.

The red-crowned crane (Grus japonensis) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240 ng/g lipid weight), followed by dichlorodiphenyltrichloroethane and its metabolites (DDTs) (150 ng/g lipid weight), chlordane-related compounds (CHLs) (36 ng/g lipid weight), hexachlorobenzene (HCB) (16 ng/g lipid weight), hexachlorocyclohexanes (HCHs) (4.4 ng/g lipid weight), polybrominated diphenyl ethers (PBDEs) (1.8 ng/g lipid weight), and finally, Mirex (1.5 ng/g lipid weight). Additionally, a positive correlation was found among POP concentrations. No sex differences beyond body parameters were observed. Additionally, red-crowned cranes exhibited a high enantiomeric excess of (+)-alpha-HCH, with enantiomer fractions varying from 0.51 to 0.87 (average: 0.69).