Effects of pulp and paper mill effluents on the reproductive and physiological status of perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) during the spawning period

Reproductive and physiological parameters were studied during the spawning period in perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) downs tream of two pulp and paper mills and reference sites in southern Lake Saim aa, Finland. plasma 17 beta-estradiol (E-2) and testosterone (T) concentrat ions in female perch and roach decreased during the spawning period. At one of the mill sites, plasma E-2 and T concentrations in pre-spawn female and male perch and male roach were significantly higher. As compared with the reference sites, liver ethoxyresorufin O-deethylase (EROD) activity in expo sed perch and male roach was 29%-91% higher, and for exposed female roach i t was 53%-79% lower. In contrary to perch, EROD activity in male roach was higher than in females. Resin acids concentration in the bile of exposed fi sh (0.2-2.0 mu g ml(-1)) was higher than at the reference sites, whereas ch lorophenolics concentration was similar (0.4-0.7 mu g ml(-1)). Results indi cate that exposure to pulp and paper mill compounds still exists, although much lower than before implementation of ECF bleaching and activated sludge wastewater treatment at the mills. Effects of pulp and paper mill effluent on reproduction of spawning fish were inconclusive.