Brooks, Bryan W.Bian, Jingyi, 1985-Baylor University. Dept. of Environmental Science.2011-05-122011-05-122011-052011-05-12http://hdl.handle.net/2104/8119Though nutrients and silver often co-occur in aquatic ecosystems, the combined effects of these environmental stressors on aquatic plants are poorly understood. Such coexposures are important because nanosilver is increasingly released to the environment, and recent studies indicate that the dissolved fraction of nanosilver appears to be more acutely toxic to aquatic life. The primary objective of this study was to understand the effects of nitrogen (N) and phosphorus (P) concentrations and N : P ratios on the toxicity of ionic silver toxicity to the model aquatic macrophyte Lemna gibba over 7-d study periods. The experimental results indicated that L. gibba were more sensitive to silver (e.g., lower EC50 values) when N and P concentrations were higher. In addition, greater ionic silver toxicity occurred under higher P-availability (e.g., lower N : P ratios) conditions. L. gibba frond number and fresh weight were also differentially affected and showed variable sensitivity to different nutrient x silver treatment combinations, which highlights the importance of considering site-specific nutrient conditions during the prospective and retrospective assessment and management of silver impacts to primary producers.66200 bytes366510 bytesapplication/pdfapplication/pdfen-USBaylor University theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact librarywebmaster@baylor.edu for inquiries about permission.Aquatic ecosystems.Nutrients.Aquatic toxicity.ThesisWorldwide access.Access changed 6/26/13.