Spatial-Temporal Changes of Nutrients in Muskoka River, an Example of Undeveloped Area
Huaxia Yao, ON Ministry of Environment and Climate Change, [email protected]
Tim Field, Nipissing University, [email protected]
Chris McConnell, ON Ministry of Environment, [email protected]
April James, Nipissing University, [email protected]
Abstract
Nutrients and their changes in space and time have been monitored and studied for many watersheds draining to the Great Lakes. Nutrient concentration and loading within undeveloped areas are reported relatively less than the developed or polluted areas. This study presents nutrient changes within a small Muskoka River Watershed (5,000 km2, 60,000 people, no manufacturing industries) over a long time span of 33 years. Based on monthly water quality monitoring at eight locations along Muskoka River in 2015-2016, spatial variations of concentration and areal loading differ among nutrients. Base cations, chloride, DIC and copper increased from the upper reach to the middle or lower reach of the river, probably due to enhanced human residence and activities. Ammonium, DOC, total phosphorous, most metals decreased along the river, due to nutrient sedimentation and/or biological consumption; while sulphate, nitrate and organic nitrogen did not change substantially over space. Within a year, the nutrient concentration varied seasonally, and the seasonal variation differed among nutrients. Comparing 1983 and 2016, all nutrients except Cl and Na declined due to reduced acid rain and atmospheric deposition, indicating a different pattern between undeveloped and developed areas.
1. Keyword
nutrients
2. Keyword
spatial distribution
3. Keyword
monitoring
4. Additional Keyword
Muskoka River
5. Additional Keyword
loading
6. Additional Keyword
temporal