Date of Graduation
Bachelor of Arts
Department or Program
Number of Pages
The over 6000 lakes in the State of Maine drive the local economy and provoke tourists to take advantage of the many recreational opportunities on the lakes that span the entire state (Smith 2003). A universal expression of water quality is “transparency”, or the depth that a Secchi disk is viewable from the surface of a water body (Steel and Neuhausser 2002). In the State of Maine, volunteer water quality monitors have collected this data since 1971 as part of the Maine Volunteer Lake Monitoring Program. Scott Williams of the Maine Volunteer Lake Monitoring Program and Linda Bacon of The Lakes Program at the Maine Department of Environmental Protection noticed a correlation between precipitation in Gray, Maine and Secchi disk measurements collected by volunteers throughout the State of Maine from 1975-2011. To further investigate this correlation, Maine VLMP Secchi transparency data was separated into two categories, those lakes that were within 120 km of the National Weather Service in Gray, ME (where the precipitation data was collected) and all VLMP monitored lakes statewide for the period of 2001 – 2011 and precipitation periods analyzed. For all Maine VLMP lakes the correlation between Secchi depth and precipitation from 2001- 2011 is equally strong in April through July precipitation as that that occurs between January and July at R2 = 0.73 and R2 = 0.72 respectively. This indicates that winter precipitation is not as strong a predictor of Secchi transparency as the period from April – July. Precipitation was not a strong indicator of Secchi Depth for lakes within 120 km of Gray, ME, indicating that there are other drivers of Secchi depth in areas with increased urban development. This study provides investigation in the ongoing understanding of the ability of precipitation to predict Secchi transparency in Maine lakes.
Epstein, James R., "Transparency in Maine Lakes: Response of Secchi Depth to Precipitation" (2013). Standard Theses. 14.