RP5 Endocrine Disruption and Pharmaceutical Issues
Thursday, 17 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(MIL-1117-722556) Extrapolation of a molecular response to population impacts: vitellogenin in fish.

Miller, D.¹, Jensen, K.², Villeneuve, D.², Ankley, G.², ¹ US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, MidContinent Ecology Division, Grosse Ile, Michigan, USA² US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, MidContinent Ecology Division, Duluth, Minnesota, USA

ABSTRACT- A challenge in the field of ecotoxicology is the linkage of alterations at molecular and biochemical levels of organization to adverse outcomes in individuals and populations. In the present study, a predictive relationship between decreased vitellogenin concentration and decreased fecundity in female fathead minnows (Pimephales promelas) was derived from short-term, 21-d laboratory toxicity tests with fadrozole, 17-trenbolone, 17-trenbolone, prochloraz, fenarimol, and ketoconazole exposures. The relationship between decreased vitellogenin and decreased fecundity at the organismal level was utilized within a population model to translate changes in vitellogenin concentrations of the female fathead minnow to alterations in population growth rate. Application of the model requires only a life table, a measure of carrying capacity for a given population of interest, and estimation of vitellogenin concentrations within the fish of the study population. Example applications are provided using different projection scenarios for a population of fathead minnows exposed to chemical stressors that reduce vitellogenin concentrations in the female, decrease fecundity, and thus reduce recruitment to a population. This research approach could be applied to other species as a population-level analysis tool for use in interpreting the effects of multiple stressors that have a common measurable organismal level effect. This abstract does not necessarily reflect EPA policy.

Key words: fathead minnow, vitellogenin, fecundity, population projection