Evaluation of Fish Species Tolerances to Environmental Stressors in Lakes in the Northeastern United States

Abstract

We present a simple quantitative visual method to aid in evaluating fish species tolerances to environmental stressors. To illustrate this process, we evaluated tolerances to five variables indicative of ecosystem stress—eutrophication, turbidity, human activity in the watershed and along the shoreline, and species introductions—for 42 fish species. Fish were collected from 169 lakes that were sampled by the Environmental Monitoring and Assessment Program (EMAP) in the northeastern United States. We integrated each species tolerance to the individual stressors into an overall tolerance rating for use in developing metrics for an index of biotic integrity. Eight species usually classified as tolerant or moderately tolerant of disturbance in streams appear to be intolerant or moderately intolerant of degraded conditions in lakes. Five species usually classified as intermediately tolerant in streams are very tolerant in northeastern U.S. lakes.

Notes

¹ Field and laboratory data from the Northeast Lakes Pilot may be found on the EMAP website (http://www.epa.gov/emap/html/dataI/surfwatr/data/nelakes).