Sexual difference in mercury concentrations of lake trout ( Salvelinus namaycush) from Lake Ontario

• Published in: Chemosphere (Oxford) 2011-05, Vol.83 (7), p.903-908
• Main Authors: Madenjian, Charles P., Keir, Michael J., Whittle, D. Michael
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Bioenergetics modeling; Biological and medical sciences; Contaminants; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Environmental Monitoring; Excretion rates; Female; Females; Fresh Water - chemistry; Fundamental and applied biological sciences. Psychology; Great Lakes Region; Gross growth efficiency; Lake Ontario; Lake trout; Lakes; Male; Males; Mercury; Mercury - metabolism; Polychlorinated biphenyls; Salvelinus namaycush; Sex Factors; Sexual differences; Trout; Trout - metabolism; Water Pollutants, Chemical - metabolism; Water Pollution, Chemical - statistics & numerical data
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2011.02.053

► Hg concentration in male lake trout was 8% greater than that in female lake trout. ► Bioenergetics modeling did not account for this difference. ► Difference may still be due to sexual difference in gross growth efficiency. ► PCB concentration in male lake trout was 22% greater than that in females. ► Direct uptake and excretion was likely more important for Hg than for PCBs. We determined total mercury (Hg) concentrations in 50 female lake trout ( Salvelinus namaycush) and 69 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). Results showed that, on average, males were 8% higher in Hg concentration than females in Lake Ontario. We also used bioenergetics modeling to determine whether a sexual difference in gross growth efficiency (GGE) could explain the observed sexual difference in Hg concentrations. According to the bioenergetics modeling results, male GGE was about 3% higher than female GGE, on average. Although the bioenergetics modeling could not explain the higher Hg concentrations exhibited by the males, a sexual difference in GGE remained a plausible explanation for the sexual difference in Hg concentrations of the lake trout. In an earlier study, male lake trout from Lake Ontario were found to be 22% higher in polychlorinated biphenyl (PCB) concentration than females from Lake Ontario. Thus, although males were higher in both Hg and PCB concentrations, the degree of the sexual difference in concentration varied between the two contaminants. Further research on sexual differences in Hg excretion rates and Hg direct uptake rates may be needed to resolve the disparity in results between the two contaminants.