Changes in growth and secondary sex characteristics of fathead minnows exposed to bleached sulfite mill effluent

Abstract

Yellow perch captured downstream of a bleached sulfite mill had reduced gonad size and fecundity, and circulating steroid levels declined in goldfish exposed to final effluent for 21 d. To assess bleached sulfite mill (BSM) effluent, long-term fathead minnow (Pimephales promelas) growth and reproduction tests were carried out in a flow-through bioassay trailer at the mill secondary treatment lagoons. Fertilized P. promelas eggs were hatched in effluent (0, 1, 3.2, 10, 32, 50, and 100% final effluent with 10 ng/L ethinylestradiol as a positive control compound) and monitored through to 30, 60, and 125 d posthatch. The effluent caused a significant increase in the growth of fish; this effect was evident within 30 d. Fish had changes in secondary sex characteristics at maturity: Male fish had ovipositors in effluent concentrations as low as 3.2%. Higher effluent concentrations (32-100%) resulted in a majority of fish that looked externally like females. Changes in external sex characteristics were the most sensitive endocrine disruption-specific endpoints and required four months of exposure. Exposure to low BSM effluent concentrations (3.2%) resulted in female fish that had male sex characteristics (tubercles and dorsal fin dots). This masculinization of female fish was statistically significant at 10% effluent and was not seen in control fish. Concentrations of final effluent in the Saint John River (Canada) range from less than 1% to 15%, depending on the season and river flow. The research assesses some of the changes seen in fathead minnows exposed to this complex effluent, and demonstrates a threshold of <10% BSM effluent for the most sensitive effects.

An in vitro/in vivo screening assay as a sensitive tool to assess endocrine disruptive activity in surface water

“…Hence, the cause for higher HSI means in fish exposed to the river waters was probably not limited to estrogenic active compounds. Increased HSI values related to EE2 exposure were also reported in other studies (Parrott et al, 2003;Versonnen et al, 2003).…”

“…Induction of VTG in male fish has proven to be a sensitive endpoint for detection of estrogenic active EDCs as well as of effluents and surface waters (Kramer et al, 1998;Sheahan et al, 2002;Parrott et al, 2003;Jobling et al, 2004). VTG is an oestrogendependent yolk protein precursor synthesized in the liver and transported by the blood stream to the female gonads where it is incorporated in the developing oocytes.…”

Probing the xeno-oestrogenic impact of sediment cores contaminated by the pulp and paper industry: induction of aromatase cyp19a1b in late larval zebrafish

“…However, a more recent study opposed that claim, and suggested the disruption of estradiol metabolism by DHAA as an alternative explanation (Pandelides et al 2014). Occurrence of androgens in effluents from bleached kraft mill (Larsson et al 2006), and bleached sulphite mill (Parrott et al 2003), could explain the potential for competitive binding of ER by AR-agonists, or even non-ER-mediated signalling, i.e. AR-based response, in exposed fish.…”

Wood production, wood technology, and biotechnological impacts

“…fathead minnow, Pimephales promelas) that can be detected in a concentrationdependent manner by the very sensitive reactions of the fishes (Parrott & Wood 2002, Parrott et al 2003, Kovacs et al 2005. Genotoxic effects of wood dusts on DNA have recently been recorded in human lymphocytes in a test system referred to as Comet assay (Faust et al 2004).…”