Technical Bulletin No. 0986: Effects of Effluents from Two Mills with Douglas Fir Furnish on Early Life Stages and Life Cycles of the Fathead Minnow and Ceriodaphnia dubia

Effluents from an unbleached kraft mill on one river and a bleached kraft mill on another were evaluated using Ceriodaphnia dubia whole effluent toxicity acute and chronic tests and fathead minnow (Pimephales promelas) 7-d and life-cycle tests. Measured life-cycle test endpoints included fish growth and survival, egg production (eggs/female/day), gonadosomatic index (GSI), hepatosomatic index (LSI), condition factor (K), number of tubercles on heads of males and females, and gonadal histology. These bioassays were conducted to investigate effluent dose-response patterns of survival, growth, and reproduction in laboratory test organisms.