Human activity within the watershed can greatly accelerate the eutrophication process by increasing the rate at which nutrients such as phosphorus and nitrogen enter the lake (Fernandez et al. 1992). Increased nutrient loading causes dramatic increases in algal populations resulting in algal blooms. Many New England lakes develop a greenish tint because of algal blooms during early summer or early fall. Populations of bacteria which feed on organic material rise because of increased food supply. Bacterial activity decreases the level of dissolved oxygen in the lake (Henderson-Seller and Markland, 1987). A sharp decrease in dissolved oxygen levels can cause massive death of many lake fauna especially fish, a process known as fish kill. While this process is not yet occurring at North Pond or Little Pond, it could occur in the future depending on the activity of local residents.
North Pond and Little Pond include the communities of Smithfield, Mercer, Rome and Norridgewock as shown on United States Geological Survey topographical maps. They are located in the Belgrade Lakes region of south-central Maine. The watershed is approximately 487,400 acres. More than half of the watershed (55%) is found in Smithfield. Mercer comprises 30% and Rome is slightly more than 10% of the watershed. Norridgewock only contains 1% of the watershed.
North Pond and Little Pond receive nutrient inputs from many different sources both natural and manmade. Natural sources such as Serpentine, Pattee Brook, Leech Brook and Bog Stream carry nutrients from their surroundings to the lake on suspended particles and dissolved in the water. Activities and developments such as roads, construction, logging, and human waste disposal in subsurface waste disposal systems have negative effects on water quality. They contribute unnaturally high levels of nutrients and suspended particles which will carry nutrients to the lake or its tributaries and eventually empty into the lake. The lake is also used for recreational swimming, boating, fishing, hunting and as a source of drinking water. A gravel pit, several tree farms and airfield are also located within the watershed.
Historically, North Pond has not suffered from algal blooms like East Pond which has seasonal algal blooms because of high nutrient levels (BI493, 1991). However, if human activity is not monitored and development carefully controlled, North Pond’s nutrient cycle could be accelerated resulting in algal blooms, poor water quality, and fish kills.
The major purpose of this study is to asses the current land use patterns and their influences on the water quality of North Pond and Little Pond, including biotic and abiotic parameters which are involved. Additionally several other parts of the study are: 1) assess the potential for nutrient loading from road runoff, tributaries, residential areas, and other human activities within the watershed, 2) determine the influence of current and historical land use patterns on the lake water quality - calculate flushing rate and water budget for North Pond and Little Ponds, 3) use gathered information to construct phosphorus and nutrient level equation which will allow projections of future condition of water quality considering specific changes in human practices surrounding the lake, and 4) make recommendations to North Pond Lake Association, Maine Department of Environmental Projection, and the towns of Mercer, Smithfield, Norridgewock, and Rome based on findings.
Problems in Environmental Science course (Biology 493), Colby College and Colby Environmental Assessment Team, Colby College, "Land Use Patterns in Relation to Lake Water Quality in the North Pond Watershed" (1996). Colby College Watershed Study: East and North Ponds (2011, 1999, 1996, 1991). 3.
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