HISTORY OF LAND USE AND EUTROPHICATION AT SHAKAMAK STATE PARK, IN

Shakamak State Park, established in 1929, is located in the center of Clay, Green and Sullivan counties in Indiana. Lake Shakamak, located within the park, is a 56 acre impoundment constructed in 1930 when drainage through the railroad grade was blocked. Lake Shakamak and neighboring Lake Lenape are currently considered sub-impoundments, both of which drain directly into a third impoundment constructed in 1969, Lake Kickapoo. Lakes Shakamak and Lenape trap significant amounts sediment and nutrients that enter the system from the surrounding landscape before they enter Lake Kickapoo. Nutrient utilization is evident in the comparison of dissolved oxygen levels amongst the lakes. Lake Shakamak is the most eutrophic of the three impoundments with dissolved oxygen values of 5ppm 6ft below the water surface. Here we present preliminary finding of a paleolimnological eutrophication study using fossil diatoms and geochemical analyses from sediment cores collected from Shakamak, Lenape, and Kickapoo Lakes. The goal of our study is to better understand anthropogenic impact on the ecosystem throughout the history of these closely-related lakes. This research provides an analysis of the current trophic status of the lakes as well as the context for how the nutrient status of the lakes has changed through time and potential identification of sources of nutrient loading to the system. Several underground coal mines preexisted near the drainage basin that may have an influence on the water quality.