Department or Program

Environmental Studies


Lake Auburn, the source of Lewiston and Auburn drinking water, is a dimictic mesotrophic lake located in Auburn Maine. The lake’s pristine nature allows for water, under strict guidelines, to be processed for drinking without the need or requirement for filtration. The lake must maintain relatively clear water in order to continue to be a filterless drinking water supply. Past water treatments have been undertaken to maintain clear water. A closer look was taken at the community dynamics of Lake Auburn’s plankton in an effort to better predict when costly and disturbing water treatments should be administered. Over fifty taxa were identified, and a total of 34 taxa were consistently counted and recorded. Of particular interest were also the reproductive habits of the cyanobacteria Gloeotrichia. It was found that the Gloeotrichia population as a whole divided about one week prior to reaching its maximum abundance late summer. Only a weak negative correlation was found between Secchi depths and Gloeotrichia abundance. Water clarity did not improve later in the season when Gloeotrichia abundance diminished suggesting that other plankton or abiotic factors are responsible for low visibility in the fall. Dolichospermum was found to have consistently high to medium abundance as was the prior findings of Ana Urbina in 2016. Bosmina cladocerans, nauplii copepods, and vorticella ciliates, all reached strong apexes during the low visibility period in the fall and could be a potential indicator of failing water conditions. Future studies in Lake Auburn's planktonic assemblage should focus on investigating these taxa and their relationships inside the plankton community.

Level of Access

Open Access

First Advisor

Holly Ewing

Date of Graduation


Degree Name

Bachelor of Arts

Number of Pages


Community Engagement


Open Access

Available to all.