Date of Award

2015

Degree Type

Thesis

Department

Biological, Geological and Environmental Sciences

First Advisor

Yuan, Fasong

Subject Headings

Environmental Geology, enviromental science, limnology, anthropogenic, environment, lake, sediment, diatoms, aquatic systems

Abstract

Sediment core archives provide a history of data useful for serving as a long-term monitoring reserve to evaluate chronological events of contamination to lake systems. This could be an effective tool for continual environmental management, monitoring and potential restoration efforts. This method is also very cost-effective without the addition of a water quality monitoring station on site. Taking 3 sediment cores from Punderson Lake Ohio for analysis has allowed associating variations in select metals to anthropogenic events or activities we can determine a time frame with limited uncertainty and resolve the intensity of anthropogenic contamination to the lake starting with post World War II contamination till the present. We used sedimentation rate in conjunction with radiometric dating methods of 137Cs to establish a timeline through the cores. Applying mass depth g/cm2 (Matisoff and Whiting, 2011) and core segmentation intervals (1cm) we can remove issue of porosity and compaction. Selected trace elements (As, Cu, Mn and Pb) were studied in these sediment cores. We can parse natural crustal sources of sediment input from anthropogenic sources using a method known as enrichment factor (EF) (Feng et al., 2004). This method requires the normalization of trace metal concentration against Al into an index/dimensionless data form (Essien et al. 2009). EF index implies a severity of contamination in a sediment interval allowing for the consideration of environmental impact, status of pollution and possibly source the contamination of the select trace metal. We can then plot EF over time to obtain relative burial times of the excess trace metals. We can then make a comparison to other regional lakes to see how anthropogenic source contamination appears in other systems. We used diatoms as a biological component as they are sensitive to ecosystem/environmental changes and preserve well in buried sediment. Therefore diatoms can be seen as responding to possible human influences that are changing the hab

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