Abstract:
Lake Pleasant is a dimictic 64-acre glacial lake in Erie County, Pennsylvania with a maximum depth of 13.7 m. The main hydrologic inputs are precipitation and groundwater. Here we compile water quality data from the last 40 years to understand how Lake Pleasant has changed. Historical data (1978-2010) was provided through several sources, and we link this to more recent data (2020-2022) to analyze long-term changes in the lake. The parameters analyzed were pH, temperature, conductivity, dissolved oxygen concentration (DO), and secchi disk depth. Over the time period of record, several changes occurred that could have influenced water quality in the lake. Average air temperature has increased by 2° C since 1978 and the Western PA Conservancy acquired land within the watershed over a period from 1990-2012. In the early 1900’s the watershed was more developed/urbanized, but has gradually shifted towards a forested community. Due to the above changes, we hypothesize that surface water temperatures will have increased over time, which could lead to a decrease in DO. In addition, due to the change in land use, we expect the lake to be clearer (i.e. deeper secchi disk readings) closer to the present day. These potential changes have implications for heat storage, stratification, nutrient availability, and productivity within the lake. We plan to present data to highlight 1) average changes in the above water quality parameters, 2) surface water changes, and 3) changes in the hypolimnion over time. Assembling historical data is critical to understanding how aquatic ecosystems have changed over time.
Team Members
Sara Haines | (Christopher Dempsey) | Gannon University
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