Department or Program

Environmental Studies

Abstract

Lake Auburn, the public drinking water supply for Lewiston and Auburn, is a low-nutrient lake that has recently experienced phytoplankton blooms. These blooms pose potential threats to water quality. Models of lake metabolism can describe the productivity of lakes and provide important insight into lake health. I used high frequency dissolved oxygen (DO) data in combination with water temperature, wind speed, and light data in a metabolism model to describe the amount of gross primary production, respiration, and net ecosystem metabolism. From 2013 to 2019, production and respiration varied year to year with 2017 and 2019 having lower production than the other years. In 2018, there were a series of intense rain events followed by a fall surge in chlorophyll a and turbidity leading the Auburn Water District / Lewiston Water Division to apply a copper-sulfate algaecide application in September 2018, and then a dual-phased alum treatment in 2019. The storm events of 2018 were not severe enough to disrupt the thermal stability of Lake Auburn, but most likely did contribute to the increase in primary producers in the lake via nutrient loading from the catchment area. The algaecide treatment coincided with the natural reduction in the amount of chlorophyll a in the lake and altered the diel DO pattern in the epilimnion. Further research must be done to determine the exact impacts of the alum treatment, but concentrations of phosphorus decreased in the lake following the second treatment phase.

Level of Access

Restricted: Campus/Bates Community Only Access

First Advisor

Holly Ewing

Date of Graduation

5-2021

Degree Name

Bachelor of Science

Number of Pages

53

Components of Thesis

1 pdf file

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