Lake Erie is under stress. The Lake Erie basin is surrounded by over 11 million people and is dominated by urbanization and agriculture. While Lake Erie’s health suffers from multiple issues such as climate change and invasive aquatic species, the rising proportion of dissolved reactive and total phosphorus is seen as the primary cause of this decline.
Although nutrients, such as phosphorus, occur naturally in the environment and are essential to plant growth, human activity is causing high quantities of phosphorus to reach our watercourses. Phosphorus can come from a variety of sources including effluent from sewage treatment plants, surface runoff from agricultural, urban and suburban lands, livestock operations, industrial sources such as power plants and vehicle exhaust. Phosphorus can be found in fertilizers, pesticides, landfill effluent, septic systems and fecal matter.
High levels of phosphorus spur the formation of algal blooms that can block sunlight to underwater plants. When the algal blooms die and decompose, they consume oxygen, resulting in “dead zones” in the water of low or no oxygen that can stress and even kill fish. Some species of blue-green algae (cyanobacteria) can be extremely toxic to humans, wildlife, livestock and pets.
The Kettle Creek watershed is a contributor of phosphorus to Lake Erie. KCCA staff collect monthly surface water samples at ten locations throughout the watershed during the ice-free season. In addition to phosphorus, these water samples are analysed for various water quality parameters such as general chemistry, nutrients, heavy metals and bacteria.
Over the last ten years, 95% of the phosphorus samples collected across the Kettle Creek watershed exceeded the Provincial Water Quality Objective (PWQO) of 0.03 mg/L. This objective is the limit for total phosphorus concentrations to prevent excessive plant growth in rivers and streams. One hundred percent of the phosphorus samples collected in Lake Whittaker over the last three years exceed the PWQO objective of 0.02 mg/L during the ice-free period. This objective is set to avoid the growth of nuisance algae, in particular cyanobacteria. Although most of the total phosphorus results exceed the PWQO, the long-term data suggests a downward trend indicating that total phosphorus levels throughout the watershed are improving slowly over time. Monitoring also helps to identify phosphorus “hotspots” in the watershed. This allows KCCA to set environmental goals and implement programs to improve water quality over time.
Monitoring phosphorus in surface water throughout the Kettle Creek watershed is a major component of the Watershed Report Card process. A watershed report card evaluates key indicators of watershed health, using provincial standards of defensible science-based research. KCCA releases a new report card every five years to provide local residents, community groups, municipalities, industries and agencies information on the health of the watershed.
Through the implementation of stewardship programs and education of local landowners combined with the long-term environmental monitoring of the watershed, KCCA is working towards improving the water quality of Kettle Creek and reducing the amount of phosphorus entering Lake Erie.