Date of Award

1996

Degree Type

Thesis

Degree Name

M.Sc.

Department

Biological Sciences

First Advisor

MacIsaac, Hugh J.,

Keywords

Biology, Limnology.

Rights

CC BY-NC-ND 4.0

Abstract

Zebra mussels (Dreissena polymorpha) have been recommended as biomonitors of metal and organic contaminants. Partitioning of hydrophobic contaminants into an organism depends on, among other factors, the lipid content of the organism. Mathematical models used to predict the fate of contaminants in the environment frequently assume that the lipid content within an organism remains constant over time, despite empirical evidence to the contrary. In this thesis, I assess the influence of temporal variation in lipid content and reproductive activity on contaminant dynamics in zebra mussels collected from western Lake Erie adjacent to the Fermi Nuclear Plant. Mussels spawned twice: first in June and again in August. Lipid content of mussels was maximal following the first spawning event and declined steadily thereafter. Principal Component Analysis separated physiological and limnological parameters into three factors: seasonal (date, lipid and temperature), reproductive (reproductive status) and limnological (Chlorophyll a, secchi depth and temperature). Multiple Regression Analyses revealed that seasonal, reproductive, and limnological factors were of equal importance. Contaminant concentrations were positively related to lipid content and reproductive status. However, the effect of spawning activity is unclear, as it did not directly affect lipid content or contaminant concentrations. These results suggest that other physiological or limnological factors may obscure the effect of spawning activity on lipid content and contaminant dynamics in zebra mussels. Examination of the lipid composition revealed that polar lipids (61% of total lipids) are dominant in zebra mussels. Concentrations of PCBs with log K$\rm \sb{OW}>5.71$ were more highly correlated with neutral lipid content than with total lipid content. This finding suggests that lipid normalization on a neutral lipid basis may be more appropriate than total lipid adjustment. Furthermore, compositional changes in lipid content may dramatically affect hydrophobic contaminant dynamics in mussels.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1996 .R65. Source: Masters Abstracts International, Volume: 37-01, page: 0189. Adviser: Hugh J. MacIsaac. Thesis (M.Sc.)--University of Windsor (Canada), 1996.

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