Deeper understanding of the factors controlling stable isotopic signatures of aquatic organisms of all trophic levels is required if we are to properly use them in food web studies and as environmental indicators. The present field study conducted in the Ste. Marguerite River system, Quebec, compared periphyton signatures found in eight reaches (sections of a river/tributary) each composed of a series of sites with different flow regimes. Similar to patterns found in the laboratory, periphyton delta13C significantly decreased with increasing water velocity. In addition, periphyton biomass positively affected periphyton delta13C. Isotopic fractionation in favour of 12C by the periphyton communities likely leads to build-up of the heavier isotope in the boundary layer of algae. This study allows a better understanding of aquatic plant delta13C fluctuations. It also suggests how much variability in aquatic consumer delta13 C can be explained by water velocity in lotic systems.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82442 |
| Date | January 2005 |
| Creators | Trudeau, Véronique |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002210693, proquestno: AAIMR12557, Theses scanned by UMI/ProQuest. |
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