PERSPECTIVES ON CANADIAN FIELD STUDIES EXAMINING THE POTENTIAL OF PULP AND PAPER-MILL EFFLUENT TO AFFECT FISH REPRODUCTION

The results and interpretations of published Canadian field studies on the reproductive status of fish in waters receiving pulp and paper mi ll effluent discharges were reviewed. Most of the information was obta ined from indicator measurements such as gonad size, fecundity, and se rum steroid levels in wild fish sampled at reference and effluent-expo sed sites. Difficulties in selecting appropriate sampling sites, natur al variability, and the ecological relevance of the indicator measurem ents were identified as major complicating factors for the interpretat ion of the field data. Consequently, it was not possible to conclude t o what extent, if any, widespread effects on fish reproduction are bei ng caused by pulp and paper mill effluents or that specific manufactur ing processes are causing such effects. Further research on the normal variability and predictive capability of reproductive indicators, for example, using an integrated approach (i.e., laboratory testing, meso cosm studies, and field work), is recommended.