Temporal and spatial variation in the amount of cadmium in the phantom midge larvae (Chaoborus spp.)

Abstract

Several factors, including body size, age, and temporal and spatial variation, which may influence the amount of cadmium (Cd) in the phantom midge larvae, Chaoborus spp., were examined in eight lakes, four from south-central Ontario (Dorset Region) and four from northwestern Ontario (Experimental Lakes Area). All three species of Chaoborus (C. punctipennis, C. trivittatus, C. flavicans) found in Chub Lake (south-central Ontario), were analyzed seasonally. One species, C. punctipennis, was collected and analyzed from all lakes. Smaller Chaoborus tended to have higher Cd concentrations (micrograms Cd/g dry weight), and lower Cd burdens (ng Cd/Animal) than larger Chaoborus. The Cd concentrations of Chaoborus in Chub Lake were lowest during the summer, which coincided with the fastest growth of the organisms. The Cd burdens differed between species, which was attributed to differences in their asynchronous life histories. Cadmium burdens and concentrations were significantly lower in the organisms from northwestern Ontario than those from south-central Ontario. Lower atmospheric deposition rates, lower Cd concentrations in the lake water, as well as life history differences, may explain these results.

Kinetics and Body Distribution of Waterborne 65Zn(II), 109Cd(II), 203Hg(II), and CH3203Hg(II) in Phantom Midge Larvae (Chaoborus americanus) and Effects of Complexing Agents

“…Concentrations of Cd(II) and Zn(II) accumulated by C. americanus larvae in this work ( V ACC × [metal] water = [metal] larvae ) () were 3−4 orders of magnitude lower than values measured in Chaoborus spp. larvae collected in the field ( − ), even if our exposure conditions were in the range of natural ones (). Cd(II) uptake via water in Chaoborus punctipennis was recently shown to be negligible compared with dietary uptake ().…”