ABSTRACT
This chapter examines potential metrics for their correlations with independent measures of the environmental quality of Wisconsin lakes and for their temporal and spatial variability when environmental quality is stable. Fish assemblages reflect the overall integrity of biological communities and are excellent indicators of the environmental quality of aquatic ecosystems. Several types of environmental indices based on fish assemblages have been developed, with the most widely used and most effective based on the Index of Biotic Integrity. The Sparkling Lake data were used to quantify within-year variation in metric values in the absence of significant changes in environmental quality. In Sparkling Lake, inclusion of young-of-year fish in calculations had different effects on species richness as estimated by seining. The proportion of individuals as intolerant species had a stronger correlation with Trophic State lndex (TSI) than the number of intolerant species for both methods; the index sample relation with TSI was stronger than the fyke sample’s for this metric as well.
