Assessing Two Centuries Of Anthropogenic Impacts On Silver Lake Summit County Ohio

Download or read book Assessing Two Centuries of Anthropogenic Impacts on Silver Lake, Summit County, Ohio written by Kelly A. Shaw and published by . This book was released on 2013 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increase in human population and human activities often negatively impacts the quality of our waters. Lake sediment often preserves a record of past anthropogenic activities and can be used to assess the impact of humans on the lake system. This study examines Silver Lake, a groundwater-fed kettle lake located in the Village of Silver Lake, Summit County, Ohio. Surface samples and water column profiles were collected to assess present-day conditions because the health of the lake is of concern to the local residents. The lake is eutrophic, with an anoxic hypolimnion during the summer months that allows phosphorus to be released from the sediment. Since 1982 lake transparency has been decreasing as evidenced by a shallowing in Secchi depth reading. Silver Lake contains two basins, and sediment cores were collected from both basins to assess longterm changes in the lake. The sediment in both basins displayed similar trends. Below 163.5 centimeters below lake floor core depth, a dark green-brown, organic-rich gyttja with relatively high C/N ratio is interpreted to represent forested watershed conditions prior to the arrival of New Englanders in 1804. The decline in sediment organic content and corresponding increase in bulk density at 125 cmblf likely reflects the impact of land clearance within the watershed following settlement. Between 79 -117.5 cmblf, a black mud having an oily odor and low organic content is present. This black mud has pronounced increases in trace metals, ferrimagnetic content, combustion particles, and bulk density, and likely was deposited between 1874 and 1918 when a major amusement park, complete with steamboat rides, occupied the western shore of the lake. This period is also inferred to contain the 1913 flood shown by an increase in Cr content. When the park closed in 1918, the land was converted into suburban housing and by the mid-late 20th century the entire watershed was occupied by suburban housing. The brown mud above 79 cmblf core depth displays decreasing trends in ferrimagnetic content, tracemetal content, and combustion particles, reflecting changes in anthropogenic activities during the mid- to late 20th century. Study of the lake sediment allows the impacts of humans on the Silver Lake system to be assessed and the present-day conditions to be placed in a long-term context.