Evaluation of trophic status for Lake Hamilton

Abstract

There were two main goals of this project, the first was to evaluate the trophic status of Lake Hamilton, using empirical and simple mechanistic models. The second was to obtain a detailed data base for 1987 that could be used to model eutrophication with a sophisticated model. Field sampling was performed on 25 dates during 1987; temperature and dissolved oxygen profiles were determined at the sampling sites. Samples were collected and analyzed for soluble reactive phosphorus, total soluble phosphorus, nitrate, ammonia and chlorophyll a. Many hydrologic and morphometric parameters were calculated for Lake Hamilton. Also, the large amount of data collected for the lake is suitable for future use in more detailed water quality modeling. Lake Hamilton trophic status was predicted to be eutrophic using Vollenweider's (1975) loading plot. Based on the procedure of Dillon and Rigler (1975), the phosphorus loading to Lake Hamilton was estimated to be 2524 kg/Yr. It was also estimated that a 60% reduction in phosphorus loading would be required to improve the lake from a eutrophic to a mesotrophic condition.