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Asylum lake is an urban lake in Kalamazoo, Michigan. The lake is located near the intersection of two major roadways which are heavily salted during the winter. Wintergreen lake is a rural lake that is on the property of the Kellogg Biological Station in Augusta, Michigan. The lake is surrounded by the Kellogg Bird Sanctuary and is relatively isolated from major roadways. Both lakes are eutrophic, Asylum lake because of high salinity and lack of turnover (Macleod, et aI., 2011) and Wintergreen lake because of high nutrient inputs (Threlkeld, 1979). Previous work suggests that road salt deicers can change the physical mixing and redox structure of kettle lakes, resulting in anoxic, redox-stratified hypolimnia. To determine the effects of salinization and eutrophication on methane concentrations in these lakes, water samples were collected on two dates at one meter depth intervals from the surface to the lake bottom (14 meters in Asylum lake and 5 meters in Wintergreen lake). In situ measurements of temperature, dissolved oxygen, conductivity and pH were taken in the field at 0.5 m depth intervals using a YSI Multiprobe Sonde. Water samples were analyzed for bromide, chloride, fluoride, and nitrite using Ion Chromatography (Ie) and alkalinity, ammonium, iron(II), manganese(II), phosphate, and sulfide using UV-Vis Spectrophotometry (UV-Vis). Methane analyses were conducted at the University of Georgia (UGA) using Gas Chromatography (Ge). The results indicate that Asylum lake (urban) has more than 10 times the chloride concentration as Wintergreen lake (rural), as well as significantly higher concentrations of methane at the bottom of the water column.
Kiekhaefer, Rebecca, "The Effects of Eutrophication and Salinization on Methane Production in Urban and Rural Lakes" (2013). Honors Theses. 2252.
Honors Thesis-Open Access