SS4.03 Factors Controlling the Bioavailability and Bioaccumulation of Inorganic and Organic Chemicals into Aquatic Food Chains
Date: Thursday, June 13, 2002
Location: Poster Session - VCC
 
KovecsesJL, McGill University, Montreal, Canada, jkovecses@hotmail.com
Rasmussen, J, B, McGill University, Montreal, Canada, jrasmu@bio1.lan.mcgill.ca
 
DO ONTOGENETIC DIET SHIFTS ALTER METAL EXPOSURE IN FISH?
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Although there is sufficient evidence to indicate that fish can accumulate metals from their diet, there have been few investigations into how this exposure will change as fish diet changes. Benthic invertebrates are important prey items in the diets of many freshwater fish. As a result of living in metal-contaminated sediments, benthic invertebrates tend to accumulate high concentrations of metals in polluted systems. Over the course of growth, many fish switch from a planktivorous diet to a benthivorous diet. This switch may potentially increase their exposure to metals due to feeding on more contaminated prey. We collected invertebrates and perch (Perca flavescens) from lakes along a gradient of metal pollution in Rouyn-Noranda, Qc., which has a long history of Cu smelting. Using stable isotope analysis, gut content analysis and metal analysis of perch livers, we determined how the metal exposure to perch changes as they switch from a planktivorous diet to a littoral, benthic diet. We show that proportion of benthivory in the diet is correlated to the concentration of metals in the liver of perch.