Title

Distribution of bioavailable organic contaminants in the lower food web of morphologically distinct freshwater lakes.

Date of Award

2005

Degree Type

Thesis

Degree Name

M.Sc.

Department

Biological Sciences

Keywords

Biology, Limnology.

Rights

CC BY-NC-ND 4.0

Abstract

This study focuses on limnological processes that impact Hydrophobic Organic Contaminant (HOC) cycling within the lower food web components of freshwater lakes. Four lake systems were selected to test if mixing profiles and lake thermostructure contribute to fugacity gradients between different components of the lower food web. To test the hypotheses, net plankton (63 and 150mum mesh), benthos, sediments and water chemistry parameters were collected from both well mixed and thermally stratified lakes in Southern Ontario during open water periods of 2002 and 2003. Calibrated mussel ( Elliptio complanata) biomonitors were deployed in containment cages to track HOC residues in the water column. Total PCB concentrations in pelagic biota across all lakes ranged from 14.9--226ng/g in net plankton, and 8.3--734ng/g in steady-state corrected mussel tissue (lipid). Spring mussel PCB concentrations were found to be significantly higher than all other collection dates in three of four lakes, reflecting a contaminant pulse due to spring runoff event. This PCB concentration trend was not correlated with mixing cycles as was originally predicted. Total PCB concentrations in sediments (3--120ng/g OC-normalized) and Chironimidae (75.9--791ng/g lipid) from deep stratified lakes were higher than shallow well mixed littoral areas within the same lakes, but this trend based on mixing cycles was not observed across lakes. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .H34. Source: Masters Abstracts International, Volume: 44-03, page: 1286. Thesis (M.Sc.)--University of Windsor (Canada), 2005.