Currently there are three companies producing bitumen from the Athabasca Oil Sands Region located near Fort McMurray, Alberta, Canada. Extraction of bitumen produces solid (sand) and liquid (water with suspended fine particles) tailings material, called oil sands process affected-materials (OSPM). These waste materials are stored on site due to a zero discharge policy and must be reclaimed when operations end. The OSPM is known to contain naphthenic acids (NAs) and polycyclic aromatic hydrocarbons (PAHs) and has high pH and salinity. A possible method of reclamation is the wet landscape approach, which involves using OSPM to form wetlands that would mimic natural wetland ecological functioning. This study investigated the effects of wetlands formed with OSPM on wood frog larvae (<i>Rana sylvatica</i>), using endpoints including survival, growth, time to metamorphosis, hormonal status, and detoxification enzyme induction [ethoxyresorufin-o-dealkylase (EROD) activity].<p>
<i>In-situ</i> caging studies were completed in 2006 and 2007. Four wetlands were studied in 2006 and 14 wetlands were studied in 2007. The 2006 season saw a host of problems that were resolved for the 2007 season. In 2006, tadpole survival did not differ among reference wetlands and old OSPM-affected wetlands but there was 100% mortality of tadpoles in the young OSPM-affected sites that contain the highest concentration of toxic components. Results were similar in 2007, with tadpoles raised in young OSPM-affected wetlands having 41.5%, 62.6%, and 54.7% higher tadpole mortality than old OSPM-affected, young reference, and old reference wetlands, respectively. In 2007, tadpoles from young OSPM-affected sites had delayed metamorphosis (12 days longer than tadpoles from old reference wetlands and 18 days longer than tadpoles in old OSPM-affected wetlands). The thyroid hormone ratios of tadpoles in young OSPM-affected wetlands were between 25% and 42% lower than tadpoles in all other wetlands groups. The EROD activity of tadpoles in young OSPM-affected wetlands was an average 223% higher than those in old OSPM-affected wetlands, showing us that tadpoles were responding to higher levels of contaminants in young OSPM-affected wetlands. Size differences were only noted in 2007, most likely not as a result of exposure to OSPM, but due to differences in population density. The results of this study lead us to believe that toxicity due to OSPM decreases as wetlands get older and OSPM-affected wetlands could support native amphibian populations if they are allowed to mature. Since we considered wetlands to be old if they were seven years or older and the fact that old-OSPM wetlands showed effects on tadpoles similar to those of reference wetlands and showed much less toxicity than young OSPM-affected wetlands, we believe wetlands that are at least seven years old would sustain amphibian life.
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-03122009-143350 |
| Date | 12 March 2009 |
| Creators | Hersikorn, Blair Donald |
| Contributors | Smits, Judit, Flood, Peter F., Blakley, Barry R., Wickstrom, Mark |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-03122009-143350/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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