Endpoints for Responses of Fish to Chronic Toxic Exposures

Abstract

The concept of chronic toxicity has caused confusion in fish toxicology because it has developed four connotations: long duration, inclusion of all life stages, low severity, and high sensitivity. To compare alternate chronic tests and expressions of test results, we extracted concentration‐response data from published life‐cycle, partial‐life‐cycle, and early life‐stage tests and derived concentration‐response relationships by nonlinear regression. The effects examined were reductions in parental survival, fecundity, hatching success, larval survival, weight of early juveniles, and weight of early juveniles per egg. On the average, the most sensitive effect was reduction in fecundity, not effects on early life stages. We also found that maximum acceptable toxicant concentrations (MATCs) corresponded to fairly high levels of effect; mean reductions at the MATC were parental survival, 20%; fecundity, 42%; hatching, 12%; larval survival, 19%; weight, 20%; and weight/egg, 35%. These results indicate that, on average, MATCs are concentrations that cause substantial effects and that MATCs estimated from early life‐stage tests are not good substitutes for life‐cycle tests. We suggest that the acute‐chronic dichotomy be abandoned in favor of tests and benchmarks based on concentration‐duration‐response dynamics.

Report of the OECD Workshop on Statistical Analysis of Aquatic Toxicity Data

“…They concluded that the shortcomings of the NOEC provide an incentive to develop model-based methods for expressing the relationship between concentration and effect. Barnthouse et al (1987) and Suter et al (1987) both commented on the fact that 'large' effects may be present at 'safe' concentrations. This is a direct consequence of the statistical power of the testing procedures.…”

Oak Ridge Y-12 Plant Biological Monitoring and Abatement Program Plan

“…The ability to successfully reproduce is essential for the establishment and continued maintenance of viable fish populations. In addition, certain reproductive processes, including egg production (Suter et al 1987) and embryonic development (Adams and Greeley 1993) …”

Approach and Strategy for Performing Ecological Risk Assessments for the Department of Energy Oak Ridge Field Office Environmental Restoration Program

“…The Chronic National Ambient Water Quality Criteria (NAWQC) for Protection of Aquatic Life are based on thresholds for statistically significant effects on individual responses of fish and aquatic invertebrates. Those thresholds correspond to approximately 25% reductions in the parameters of fish chronic tests (Suter et al 1987). Because of the compounding of individual responses across life stages, the chronic NAWQC frequently correspond to much more than 20% effects on a continuously-exposed fish population (Barnthouse et al 1990).…”