Total Phosphorus & Benthics
To determine surface water quality, biologists sampled creeks and lakes for things like insects, mollusks, crustaceans, and worms. As well, water quality specialists collected water samples to test for total phosphorus levels, which were also used to determine the health of a stream. Together, Benthic Macroinvertebrates and Total Phosphorus provide chemical and biological indicators of water quality, which we used to grade the ten Kawartha watersheds included in the Greenbelt/ORM analysis.
Benthic Macroinvertebrates (BMI), the insects and other aquatic organisms that live on the streambed, are excellent indicators of stream health. They are generally abundant, easy to sample, relatively stationary, and sensitive to environmental stressors such as pollution. We calculated the grades based on five years of sampling data, from 2008 to 2013 using the Hilsenhoff 1988 Family Biotic Index (FBI. Five years of sampling data within the period 2008 to 2013 were used to calculate the grades. Where necessary, data from earlier years was used to increase the number of sites available for analysis to achieve a valid sample size.
Phosphorus is a nutrient that helps us determine the health of lakes and rivers. Too much in the water from fertilizer, septic systems, erosion, and other sources, can cause the water body experience algae blooms and increased aquatic plant growth, decrease the amount of oxygen available to fish, and decrease water clarity. Provincial Water Quality Objectives suggest that Total Phosphorus levels greater than 0.03 mg/L result in unhealthy stream conditions. We used a minimum of monthly sampling data from 2008 to 2013 with 30 or more data points for the grading.