Changes in growth, secondary sex characteristics, and reproduction of fathead minnows exposed for a life cycle to bleached sulfite mill effluent.
To assess the potential effects of exposure to bleached sulfite mill effluent, long-term fathead minnow (Pimephales promelas) exposures were carried out on-site at the pulp mill secondary treatment lagoons. Exposure concentrations included 0, 1, 3, 10, 30, 50, or 100% final effluent, with the synthetic estrogen ethinylestradiol (10 ng/L) as a positive control compound. Fertilized minnow eggs were hatched in effluent and monitored through 140 d posthatch. The effluent produced a significant increase in the growth (length, weight, condition factor) of female fish (but not male fish). Exposure to high effluent concentrations resulted in a majority of fish with female secondary sex characteristics. Male fish with female characteristics and female fish with male sex characteristics were present at effluent concentrations of > or = 30%, but not in fish exposed to control water from the Saint John River. Effluent exposures (> or = 30%) also produced a reduction in the number of fish with testes, and most fish had ovaries when examined internally. A sensitive and meaningful endpoint was a decrease in reproduction. Fish exposed to 1 - 3% effluent produced a similar number of eggs to control fish; however, exposure to 10% effluent reduced egg production by over 80%. Fish exposed for an entire life cycle to > or = 30% effluent failed to produce eggs. The research demonstrates the feasibility and potential usefulness of on-site flow-through fish life-cycle exposures for the assessment of pulp mill final effluents.
Parrott
Joanne
J
Aquatic Ecosystem Protection Research Branch, National Water Research Institute, Environment Canada, Burlington, Ontario, Canada. joanne.parrott@ec.gc.ca
Wood
Craig
C
Boutot
Peter
P
Dunn
Susan
S
D000818:Animals; D003530:Cyprinidae / Q000254:growth & development*; D005260:Female; D006066:Gonads / Q000187:drug effects; D007220:Industrial Waste / Q000009:adverse effects*; D008297:Male; D012098:Reproduction / Q000187:drug effects; D012727:Sex Characteristics; D013447:Sulfites / Q000009:adverse effects*; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
D007220:Industrial Waste; D013447:Sulfites; D014874:Water Pollutants, Chemical