<p> There have been many human-caused alterations to the Illinois River which have significantly changed the life histories of the fish and added pollution sources that could appear in the fishes. My hypothesis is that changes in the δ<sup>13</sup>C and δ<sup>15</sup>N isotopes between prehistoric and modern fishes will show differences in where the fish foraged and their trophic level in the River food chain. It is likely that these changed with human modification of the river. Stable isotopes of nitrogen and carbon vary with food source in fishes. Prehistoric Native American middens contain fish bones that represent a baseline for modern fish communities, which can be used to determine changes in the river. We have used the isotopic composition of both modern and prehistoric fish to understand changes in fish in the River. Bone collagen was analyzed in order to reduce the chances of contamination in our samples. My results show little change in fish life history, but large increases in 15N demonstrate nitrogen pollution of the river.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:1545516 |
| Date | 02 November 2013 |
| Creators | Little, Kayla |
| Publisher | Southern Illinois University at Edwardsville |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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