title: Reproductive and biochemical biomarkers in largemouth bass sampled downstream of a pulp and paper mill in Florida.
abstract: The objective of this study was to evaluate the effects of bleached/unbleached kraft mill effluents (B/UKME) on the reproductive parameters of free-ranging Florida largemouth bass (Micropterus salmoides floridanus). The reproductive parameters measured included gonadosomatic index (GSI), histological evaluation of gonads, and plasma concentrations of vitellogenin (VTG), 17beta-estradiol, and 11-ketotestosterone (11-KT). Hepatic ethoxyresorufin-O-deethylase (EROD) activity was measured as a marker of exposure to cytochrome P450-inducing agents in these effluents. Endpoints were compared among adult bass sampled from tributary and mainstream effluent-contaminated and reference sites. Females sampled from the site closest to the mill outfall had a significant five-fold increase in EROD activity compared to bass sampled from reference streams. Although sex hormones were significantly reduced in bass from exposed sites, there were no differences in VTG and GSI across sites. The absence of organism-level responses was probably not related to a lack of sensitivity, as previous studies in our laboratory have shown that bass exposed to these effluents exhibit changes in GSI and in other measures associated with reproductive success. In females, inverse relationships were observed between VTG and GSI and EROD activity. These relationship, however, were not consistent within all of the sites studied. Collectively, our findings indicate that hepatic EROD induction is an effective marker of B/UKME exposure in largemouth bass and that it might be associated with antiestrogenic effects in this species.
authors.affiliation: Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA. marisol_sepulveda@usgs.gov
authors.forename: María S
authors.initials: MS
authors.lastname: Sepúlveda
authors.forename: Evan P
authors.initials: EP
authors.lastname: Gallagher
authors.forename: Carla M
authors.initials: CM
authors.lastname: Wieser
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Gross
mesh_terms: D000818:Animals; D001492:Bass / Q000502:physiology*; D015415:Biomarkers / Q000032:analysis; D019363:Cytochrome P-450 CYP1A1 / Q000032:analysis / Q000494:pharmacology*; D004784:Environmental Monitoring; D005260:Female; D005431:Florida; D012739:Gonadal Steroid Hormones / Q000032:analysis; D006066:Gonads / Q000166:cytology / Q000473:pathology; D007220:Industrial Waste; D008297:Male; D010209:Paper; D014819:Vitellogenins / Q000097:blood; D014874:Water Pollutants, Chemical / Q000506:poisoning*
chemical_list: D015415:Biomarkers; D012739:Gonadal Steroid Hormones; D007220:Industrial Waste; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1