Endocrine disrupting compounds and pesticides have been detected in rivers and
irrigation canals of Southern Alberta, a semiarid region with irrigation-dependent crop
production, intensive livestock operations, and a growing human population. However,
little is known about the effects of agricultural runoff or wastewater treatment plant
(WWTP) effluent in Southern Alberta on fish. Reproductive effects of WWTP effluents
from the cities of Lethbridge and Medicine Hat, as well as agricultural runoff in the
Lethbridge Northern Irrigation District canals, were investigated in a field study with
wild fathead minnows (FHMN) in the Oldman and the South Saskatchewan rivers, in
Alberta, Canada, and in a laboratory study with laboratory reared FHMN exposed in vivo
to the city of Lethbridge WWTP effluent for 21 days. Biochemical and morphological
endpoints were measured to characterize reproductive status. Liver vitellogenin, a
biomarker of exposure to estrogen mimics, was analyzed using quantitative RT-PCR, and
gonadal histology was used to determine sex, gonadal maturity, and intersex. Adverse
reproductive effects were detected in FHMN exposed for 21 days to 10 and 25% of
Lethbridge WWTP effluent. In the field, effluents from both Lethbridge and Medicine
Hat had an effect on the reproductive systems of FHMN. In canals, reproductive effects
were detected in wild fathead minnows in years when water quality in irrigation drain
canals decreased. Exposure to pesticides was estimated using acetylcholinesterase
(AChE) inhibition. Exposure to Lethbridge WWTP effluent did not inhibit AChE,
whereas results from the field study were inconclusive. In conclusion, reproductive
systems of fathead minnows in Southern Alberta were impacted by anthropogenic
chemicals. / xi, 104 leaves : ill. (some col.), maps ; 29 cm
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:ALU.w.uleth.ca/dspace#10133/2519 |
| Date | January 2009 |
| Creators | Kromrey, Natalie A., University of Lethbridge. Faculty of Arts and Science |
| Contributors | Hontela, Alice |
| Publisher | Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, c2009, Arts and Science, Department of Biological Sciences |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Relation | Thesis (University of Lethbridge. Faculty of Arts and Science) |
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