Development and sensitivity of a 12-h laboratory test with Daphnia magna Straus based on avoidance of pulp mill effluents.

Studies on avoidance of contaminants by aquatic organisms verified that such behavior may have crucial ecological implications. Yet, avoidance tests have not been considered in ecological risk assessments. This study aimed at developing a short-term test with Daphnia magna Straus based on avoidance of pulp mill effluents and at comparing its sensitivity to the standard 21 d D. magna reproduction test. The avoidance effective dilution values (12 h EDil20 and EDil50) were as sensitive as the 21 d EDil20 and EDil50 values for reproduction. Therefore, this easily standardizable short-term test can be recommended as a valuable complementary tool in ecological risk assessments.