Publication Date
2014
Document Type
Thesis
Committee Members
Chad Hammerschmidt, Ph.D. (Advisor); David Costello, Ph.D. (Committee Member); David Dominic, Ph.D. (Committee Member)
Degree Name
Master of Science (MS)
Abstract
Periphyton are of ecological importance because of their critical role at the base of aquatic food webs as primary producers and as a significant source of energy to higher trophic levels in many stream ecosystems. This study examined the toxicity of mercury (Hg) to fluvial periphyton with in situ chemical exposure substrates. Two endpoints were used to measure toxicity of either total Hg or monomethylmercury (MMHg) to periphyton: periphyton biomass and metabolic activity, as a function of Hg concentrations in either periphyton or their exposure to the contaminants from two contrasting sediment types, a low-organic, sandy sediment type (SC) and a high-organic, fine-grained sediment (WD). MMHg and total Hg accumulation was greater in periphyton exposed to sandy SC sediment, whereas our results indicated periphyton growth and metabolic activity may be reduced when exposed to organic-rich WD sediment. These results suggest that the organic content of sediment is a driving factor influencing the exposure and toxicity of MMHg and total Hg to stream periphyton, thus limiting or altering a crucial food source for primary consumers.
Page Count
46
Department or Program
Department of Earth and Environmental Sciences
Year Degree Awarded
2014
Copyright
Copyright 2014, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
