Females Exceed Males in Mercury Concentrations of Burbot Lota lota

• Published in: Archives of environmental contamination and toxicology Vol. 68; no. 4; pp. 678 - 688
• Main Authors: Madenjian, Charles P., Stapanian, Martin A., Cott, Peter A., Krabbenhoft, David P., Edwards, William H., Ogilvie, Lynn M., Mychek-Londer, Justin G., DeWild, John F.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.05.2015; Springer Nature B.V
• Subjects: Adults; Androgens; Animals; Bioaccumulation; Bioenergetics; Body weight; Canada; Concentration (composition); Contaminants; Contamination; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Feeding rates; Female; Females; Fish; Food chains; Gadiformes - metabolism; Geology; Gonads; Indicator organisms; Lake Erie; Lakes; Lota lota; Male; Males; Mercury; Mercury (metal); Mercury - metabolism; Metabolism; Monitoring/Environmental Analysis; PCB; Pollution; Polychlorinated biphenyls; Polychlorinated Biphenyls - metabolism; Sex; Sex Factors; Soil Science & Conservation; Spawning; Studies; Testes; Toxicity; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water pollution; Canada; United States > US; North America, Erie L; PNW, Canada, Northwest Terr; Canada, Northwest Terr., Great Slave L; Lake Trout; Standard Metabolic Rate; Gross Growth Efficiency; Great Slave Lake; MeHg Concentration
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-015-0131-1

Examination of differences in contaminant concentrations between the sexes of fish, across several fish species, may show clues for important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations of 25 male and 25 female adult burbot Lota lota captured in Lake Erie during summer 2011 and of 14 male and 18 female adult burbot captured in Great Slave Lake (Northwest Territories, Canada) during winter 2013. On average, females had 22 % greater Hg concentrations than males. This difference was probably not due to a greater feeding rate by females because results from previous studies based on polychlorinated biphenyl determinations of these same burbot indicated that males fed at a substantially greater rate than females. Based on our determinations of Hg concentrations in the gonads and somatic tissue of 5 ripe females and 5 ripe males, this difference was not attributable to changes in Hg concentration immediately after spawning due to the release of gametes. Furthermore, bioenergetics modeling results from previous studies indicated that growth dilution would not explain any portion of this observed difference in Hg concentrations between the sexes. We therefore conclude that this difference was most likely due to a substantially faster rate of Hg elimination by males compared with females. Male burbot exhibit among the greatest gonadosomatic indices (GSIs) of all male fishes, with their testes accounting for between 10 and 15 % of their body weight when the fish are in ripe condition. Androgens have been linked to enhanced Hg-elimination rates in other vertebrates. If androgen production is positively related to GSI, then male burbot would be expected to have among the greatest androgen levels of all fishes. Thus, we hypothesize that male burbot eliminate Hg from their bodies faster than most other male fishes and that this explains the greater Hg concentration in females compared with males.