What We Measure

In aquatic ecosystems, there are a number of nutrients needed to sustain life. Some of these nutrients are limiting, and others are widely abundant. In many Canadian lakes, phosphorus is present at low concentrations, such that it limits the amount of algae and other necessary nutrients in the food web. 

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When phosphorus levels in water increase, it provides optimal conditions for the growth of algae. If phosphorus levels reach critical concentrations, it can result in the formation of harmful algal blooms. The growth and decay of these blooms is called eutrophication, and it can cause harm to the ecosystem in a variety of ways, such as changing the pH of the water, interfering with predator-prey interactions, and lowering the amount of dissolved oxygen in the water.

 

In addition to this, bodies of water that undergo eutrophication are generally unpleasant to be around. They have an uninviting odour, as well as an off-putting appearance. In extreme situations, bodies of water that are highly eutrophic can be toxic to humans and animals. 

 

Due to the severity of the effects that eutrophication can cause on aquatic ecosystems, the Ontario Aquaculture Association (OAA) and the Ministry of Natural Resources and Forestry (MNRF) have created a guideline for phosphorus levels to remain under 0.01 mg/L, which is well below the danger concentrations that can result in algal blooms.

 

In order to ensure that these guidelines are adhered to, water column phosphorus concentrations around facilities are monitored throughout the growing season.  This extensive monitoring is designed to ensure that the amount of phosphorus entering the lake from aquaculture operations does not result in the eutrophication of our fresh waters. 

 

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