<p> This study analyzed fossil and modern freshwater bivalve mollusc
shells, from in and around lakes Ontario and Erie, for the following trace
metals: Cu, Ni, Zn, As, Pb, and Mn. Elliptio dilatata, Elliptio complanata, and Lampsilis radiata siliquoidea shells were analyzed by ICPMS for differences in shell metal levels between species and genera, through time and due to anthropogenic inputs. </p> <p> Regardless of age, all three species showed high concentrations of
Zn and Mn, and little or no changes in Cu, Ni, Zn, and Pb concentrations
with time. E. comp1anata shells were generally poorer in Pb, but richer
in As and Mn, than were the E. dilatata and L. radiata siliquoidea shells.
Fossil Elliptio samples did not posses low background, or baseline, trace
metal concentrations. These samples were richer in As, Pb, and Mn than
were modern samples from post-industrial environments. Among the modern
shells, the E. complanata showed no differences in metal concentrations
between samples from high- and low-contamination· sites, while the L.
radiata siliquoidea showed changes in Ni, As, and Mn concentrations among
the same sites. Modern L. radiata siliquoidea may be more likely to
represent environmental metal changes than are modern E. complanata.
Historical change in environmental metal concentrations of the Great Lakes
region is not recorded as a simple change in shell metal concentrations of
these freshwater bivalve molluscs. </p> / Thesis / Bachelor of Science (BSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22454 |
| Date | 04 1900 |
| Creators | Viveiros, Maria |
| Contributors | Risk, M. J., Geology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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