Live Fast and Die Young: Metal Effects on Condition and Physiology of Wild Yellow Perch from along Two Metal Contamination Gradients

This review summarizes some of the main findings of our work with the Metals in the Environment Research Network examining seasonal and regional effects on metal accumulation, growth, condition, and physiology in wild yellow perch (Perca flavescens) from 10 lakes comprising two metal contamination gradients in the industrial regions of Sudbury, Ontario and Rouyn-Noranda, Québec, Canada. The specific objectives of this review are: (1) to propose threshold tissue metal concentrations to discriminate between fish from contaminated and reference sites; (2) to identify factors that can influence metal accumulation and fish condition; and (3) to define an experimental approach for measuring metal effects in wild yellow perch. Using tissue thresholds appeared useful not only for discriminating fish from clean or contaminated environments, but also provided a simple approach to examine metabolic consequences of tissue metal accumulation. Overall, fish from Sudbury grew faster, expressed higher aerobic capacities, and died younger, but also appeared better at limiting accumulation of some metals than Rouyn-Noranda fish. The condition of the latter fish was clearly more affected by metals than Sudbury fish. Finally, our dataset allows us to propose that yellow perch are highly suitable for ecological risk assessment studies of metal effects in wild fish, but that fish size, season, and region must be considered in sampling design and that several reference sites must be studied for meaningful conclusions to be reached.