Evaluation of organochlorine pesticides and sex steroids in lower Niagara river lake Sturgeon

Abstract

As a long-lived, late-maturing species, lake sturgeon Acipenser fulvescens are vulnerable to the bioaccumulation of contaminants, which may impact reproductive physiology. The purpose of this study was to use a nondestructive method to investigate the relationship between endocrine-disrupting contaminants and sex steroids in lake sturgeon from the lower Niagara River. We screened blood plasma samples from lower Niagara River lake sturgeon (n = 63) during April and May of 2012 for concentrations of 17 organochlorine (OC) contaminants that may affect endocrine function, as well as for abnormal levels of sex steroids testosterone (T) and 17p-estradiol (E2). We found detectable levels of two OC contaminants in the blood plasma of lake sturgeon, DDE (n = 21) and γ-BHC (n = 1). In both cases, plasma contaminant concentration was well below levels known to adversely affect sturgeon reproductive physiology. In addition, qualitative analysis of chromatographs from plasma extracts did not show the presence of other peaks that matched polychlorinated biphenyl standard peaks. Comparisons of plasma steroid levels with those of others from the literature gave no indication of endocrine disruption, though plasma T levels were notably high in the lower Niagara River population. We conclude that plasma OC levels are below threshold levels found in the scientific literature that would affect lake sturgeon reproductive physiology, and that it is unlikely that significant contaminant-mediated endocrine disruption is occurring in this population.