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Ecological risk assessment in a large river‐reservoir: 8. Experimental study of the effects of polychlorinated biphenyls on reproductive success in mink
Author(s) -
Halbrook Richard S.,
Aulerich Richard J.,
Bursian Steven J.,
Lewis Lorin
Publication year - 1999
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620180409
Subject(s) - mink , zoology , biology , polychlorinated biphenyl , litter , offspring , ecotoxicology , fishery , ecology , pregnancy , genetics
As a component of an ecological risk assessment of Poplar Creek (located on the Oak Ridge Reservation [ORR]) and the Clinch River (a large river–reservoir system), fish from Poplar Creek, the Clinch River, and Atlantic Ocean were fed to ranch mink to evaluate reproductive success. Five diets, each composed of 75% fish and 25% normal ranch mink chow, were prepared. Two diets served as reference diets and contained 75% Atlantic Ocean fish or 75% Clinch River fish collected above the ORR. The fish portion of the remaining three diets contained 25, 50, and 75% fish collected from Poplar Creek and 50, 25, and 0% ocean fish, respectively. Five mink groups (eight females and two males each) were each fed one of the prepared diets for 196 days. Polychlorinated biphenyl concentrations were determined in diets and various mink tissues, ethoxyresorufin‐ O ‐deethylase (EROD) activity was determined in liver tissue, and reproductive success was evaluated. Concentrations of PCB were greatest in the diet composed of 75% Poplar Creek fish and in tissues from mink fed this diet and their offspring. There was a trend toward decreased adult female and kit weights and reduced mean litter size in mink fed diets containing 75% Poplar Creek fish; however, at 6 weeks of age, kit survival was similar among diet groups. Liver EROD activity significantly increased in adult female mink fed 50 and 75% Poplar Creek fish diets. Estimated dietary concentrations of PCBs were similar to or slightly lower than concentrations associated with adverse effects in experimentally dosed mink. Mercury (Hg) concentrations previously reported in these same mink were below that associated with adverse effects, and there was no indication of additive or synergistic effects from exposure to PCBs plus Hg. It is unlikely that population‐level reproductive effects would be observed in mink consuming fish from Poplar Creek on the ORR.