PARENT SESSION
PT5 - Fate & Effects of Metals: Aquatic Biology
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P613) A field study examining the uptake of metals in yellow perch (Perca flavescens).

Kraemer, Lisa^*,1, Campbell, Peter¹, Hare, Landis¹, ¹ Université du Québec, INRS-ETE, Ste Foy, Québec, Canada

ABSTRACT- In nature, fish are exposed to essential and non-essential trace metals in both water and food. We measured metal uptake by juvenile yellow perch (Perca flavescens) that were caught in a reference lake (low ambient metal concentrations) and held in cages in a lake with elevated levels of aqueous copper (0.06 nM Cu2+), zinc (160 nM Zn2+) and cadmium (3.4 nM Cd2+) in northwestern Quebec, Canada. Cages were made from 0.5-cm mesh-aperture netting, which allowed zooplankton to enter and leave at will, thereby exposing perch to metals in both their food and water. Fish were removed from cages over a period of 30 days, dissected and metals were measured in gills, gut, liver and kidney. Concentrations of copper and zinc in the organs of transplanted perch were not different from those of control fish after 30 days of exposure, despite the presence of elevated concentrations of both of these metals in the contaminated lake. In contrast, there was a significant increase in cadmium in both the gills and in particular the gut after 30 days of exposure. Surprisingly, Cd levels in the gut of fish transferred to the contaminated lake reached higher levels than those found in indigenous perch in the contaminated lake. The liver and kidneys also accumulated Cd but at a much slow rate than the gut. Our study suggests that under natural conditions yellow perch are able to regulate the uptake of essential metals such as copper and zinc, whereas the uptake of the non-essential metal cadmium is directly related to metal concentrations in the environment. Furthermore, prey are a major source of cadmium for yellow perch under natural conditions.

Key words: metals, accumulation, fish, transplantation