Maternal transfer of organochlorines to eggs of walleye (Stizostedion vitreum) in Lake Manitoba and western Lake Superior
Journal of Great Lakes Research
Contaminant dynamics, Fish size, Lipid, Pollutants, Reproduction
Gravid walleye were sampled from Lake Manitoba and western Lake Superior (St. Louis River) to measure the concentrations of organochlorine contaminants (OCs) in eggs and muscle and to assess the influence of maternal age and size on the transfer of OCs from mother to egg. Concentrations of most OCs in Lake Superior walleye eggs were 1 to 3 orders of magnitude greater than in Lake Manitoba eggs. Toxaphene (mean concentration (wet weight) ± 1 SE, 1580 ± 462 ng/g) and polychlorinated biphenyls (PCBs) (240 ± 24 ng/g) were the predominant OCs in Lake Superior walleye eggs, whereas DDT and metabolites (eggs 16 ± 1.5 ng/g, muscle 2.1 ± 0.36 ng/g) and PCBs (eggs 9.2 ± 0.83 ng/g, muscle 2.0 ± 2.4 ng/g) were the most common OCs in Lake Manitoba walleye eggs and female muscle. Egg size (dry mass) and the concentration of most OCs in Lake Manitoba walleye eggs were positively correlated with female length and age. This relationship was strongest for more hydrophobic OCs (e.g., PCBs) but was not significant for less hydrophobic OCs (e.g., hexachlorocyclohexanes (HCHs)). Neither egg size nor egg OC concentration of Lake Superior walleye were significantly correlated with female length or age. There was no relationship between OC concentrations in muscle tissue and female length or age of Lake Manitoba walleye. OC concentrations in Lake Manitoba walleye eggs were not correlated with concentrations in the muscle tissue of the mothers, suggesting that OCs in walleye eggs are derived from various tissues. A positive relationship between the egg:muscle ratio of PCB concentrations and the egg:muscle ratio of lipid in freshwater fish suggests that the maternal transfer of PCBs in freshwater fish is related to the relative amounts of lipid in the eggs and mother. The transfer of hydrophobic OCs from mother to eggs in freshwater fish appears to vary within and among fish species and with the hydrophobicity of the OC.
Fisk, Aaron T. and Johnston, Thomas A.. (1998). Maternal transfer of organochlorines to eggs of walleye (Stizostedion vitreum) in Lake Manitoba and western Lake Superior. Journal of Great Lakes Research, 24 (4), 917-928.