Use of White Sucker (Catostomus commersoni) Populations to Assess the Health of Aquatic Ecosystems Exposed to Low-Level Contaminant Stress

There is a need to develop inexpensive methods for evaluating contaminant impacts on aquatic ecosystems. This paper describes a simple, rapid, cost-effective mechanism for the in situ assessment of toxicant impact on fish populations. The framework assumes that changes in the death or birth rate, or alterations in the availability of food or habitat, are associated with characteristic responses of white sucker (Catostomus commersoni) populations. The responses have been grouped into five main patterns based on the population characteristics of mean age, fecundity, and condition factor. Populations which are growing, reproducing, and surviving at rates which are indistinguishable from a reference (control) population are considered to be free from adverse chemical effects. Analysis of published studies showed that white sucker populations responsed to several classes of environmental stressors in a predictable fashion and the framework suggested areas for follow-up study. The framework does have several limitations and is dependent upon the selection and appropriate sampling of a comparable reference population. Requirements for further development are discussed.