Summary

No abstract

The Canadian federal government instituted an environment effects monitoring (EEM) program for the pulp and paper industry to ensure the long-term integrity of fish populations below the discharge of mill effluents. The program is cyclical in nature (every three to four years) and one of the components of the program is an adult fish survey which monitors wild fish health in the receiving environments. Cycle 1 reports were submitted in April of 1996, and the report for the James Maclaren Inc. mill at Thurso, Quebec, suggested some responses were evident in fish downstream of the mill discharge. However, the receiving environment was subject to inputs from other potential sources or confounding factors such as farm runoff, storm sewers, municipal discharges and and upstream paper mills. A review of other Cycle 1 studies also identified a number of problems encountered during the adult fish surveys. At this time, Maclaren researchers and Environment Canada set up a collaborative research project as part of their Cycle 2 studies at the Thurso site. Objectives of the study included a comparison of Cycle 2 results to their Cycle 1 studies, an assessment of the potential for the use of forage fish in the EEM program as well as an evaluation of reference site variability in the required EEM fish parameters. Collections in 1997 confirmed an increased male yellow perch liver size downstream of the discharge, but could not confirm reproductive alterations in exposed fish. It was possible to obtain all of the required EEM fish parameters from a small forage fish species such as the johnny darter, which may reduce the influence of fish mobility and other confounding factors on fish responses at some sites. Reference site variability was not a contributing factor in evaluating fish responses to effluent sources at this site.