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

• Published in: The Science of the total environment 2010-03, Vol.408 (7), p.1725-1730
• Main Authors: Madenjian, Charles P., Keir, Michael J., Whittle, D. Michael, Noguchi, George E.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Bioenergetics modeling; Biological and medical sciences; Ecotoxicology, biological effects of pollution; Energy expenditure; Female; Females; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; General aspects. Techniques; Gonads; Gross growth efficiency; Lake Ontario; Lake trout; Lakes; Male; Males; Methods and techniques (sampling, tagging, trapping, modelling...); Ontario; Polychlorinated biphenyls; Polychlorinated Biphenyls - toxicity; Salvelinus namaycush; Sex Factors; Sexual differences; Shedding; Trout; Trout - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2009.12.024

We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout ( Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.