Persistent Link:
http://hdl.handle.net/10150/288703
Title:
Dynamics of selenium in Cibola Lake, Arizona
Author:
Villegas, Selso Valenzuela, 1952-
Issue Date:
1997
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Selenium bioaccumulates along the lower Colorado River and may impact fish and waterfowl. Selenium may be reduced in lakes or reservoirs by flushing (increasing the water exchange rate). Therefore, I monitored selenium levels in water, sediment, and bluegill (Lepomis macrochirus) in response to flushing on the Cibola NWR in the lower Colorado River Valley, California and Arizona. Selenium in the lakewater was below the detection level of 5.6 ppb wet weight (WW) but data from the US Geological Survey (1990-1995) showed that selenium levels in the water ranged from 1 to 3 ppb WW in the mainstem Colorado River 135 km upstream from Cibola Lake. There was no predictable trend in selenium in the sediment after flushing. It was the same after the first flushing, lower after the second flushing, and higher after the third flushing. Selenium levels in the biota also did not vary in a predictable way after flushing. It went up after the first flushing, down after the second flushing, and up after the third flushing. One might speculate that higher flushing rates, or continuous flushing might result in lower selenium levels in biota and sediment. However, selenium levels in the sediment (1.10 ppm DW) and bluegill (4.93 ppm DW) in Cibola Lake were not significantly different than levels in the sediment (0.86 ppm DW) and bluegill (4.83 ppm DW) in a comparable backwater lake (Mittry Lake, Arizona) that was continuously flushed. Therefore, flushing does not appear to be a viable strategy for managing selenium levels in backwater lakes along the lower Colorado River.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Environmental Sciences.; Agriculture, Fisheries and Aquaculture.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Renewable Natural Resources
Degree Grantor:
University of Arizona
Advisor:
Maughan, O. Eugene

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDynamics of selenium in Cibola Lake, Arizonaen_US
dc.creatorVillegas, Selso Valenzuela, 1952-en_US
dc.contributor.authorVillegas, Selso Valenzuela, 1952-en_US
dc.date.issued1997en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractSelenium bioaccumulates along the lower Colorado River and may impact fish and waterfowl. Selenium may be reduced in lakes or reservoirs by flushing (increasing the water exchange rate). Therefore, I monitored selenium levels in water, sediment, and bluegill (Lepomis macrochirus) in response to flushing on the Cibola NWR in the lower Colorado River Valley, California and Arizona. Selenium in the lakewater was below the detection level of 5.6 ppb wet weight (WW) but data from the US Geological Survey (1990-1995) showed that selenium levels in the water ranged from 1 to 3 ppb WW in the mainstem Colorado River 135 km upstream from Cibola Lake. There was no predictable trend in selenium in the sediment after flushing. It was the same after the first flushing, lower after the second flushing, and higher after the third flushing. Selenium levels in the biota also did not vary in a predictable way after flushing. It went up after the first flushing, down after the second flushing, and up after the third flushing. One might speculate that higher flushing rates, or continuous flushing might result in lower selenium levels in biota and sediment. However, selenium levels in the sediment (1.10 ppm DW) and bluegill (4.93 ppm DW) in Cibola Lake were not significantly different than levels in the sediment (0.86 ppm DW) and bluegill (4.83 ppm DW) in a comparable backwater lake (Mittry Lake, Arizona) that was continuously flushed. Therefore, flushing does not appear to be a viable strategy for managing selenium levels in backwater lakes along the lower Colorado River.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEnvironmental Sciences.en_US
dc.subjectAgriculture, Fisheries and Aquaculture.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineRenewable Natural Resourcesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMaughan, O. Eugeneen_US
dc.identifier.proquest9806761en_US
dc.identifier.bibrecord.b37515895en_US
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