Discussing the dangers of phosphorous in Ontario’s lakes

by robnot on November 11, 2017 - 7:15pm

Ontario’s Environmental Commissioner, Dianne Saxe, has released a report that states that the increasing amount of phosphorous is contributing the growing problem of harmful algal blooms in Ontario’s lakes (Riley, 2017). The news article gives a description of how farm practices and other agricultural works are one of the driving mechanisms behind the increase of phosphorus levels. The article also states how climate change is also a factor leading to more phosphorous inputs into the lakes and how this is contributing to the increase in the harmful algal blooms.


Plant life relies heavily on nutrients on order for them to grow. Phosphorous is one of the main nutrients that plants need and has been a driving force in the growth of harmful algal blooms (knights et al, 2017).  Algal blooms are frequent in lakes, including Lake Superior, and can cause a lot of damage. Algal blooms can cause damage to the fresh water ecosystem and reduce biodiversity. They can cover and restrict sunlight from entering the lake which can reduce subsurface plant life and deplete oxygen levels leading to a hypoxic environment (knights et al, 2017). This, in turn, will affect the aquatic life that resides in the lake and stress the ecosystems. Some types of algae can also produce toxins which can be harmful to the ecosystem but also contaminate drinking water which leads to harmful consumption by humans (knights et al, 2017).


Phosphorous makes its way into these lakes through surface and sub surface run off. Agriculture industries use phosphorous to enhance crop production and this leads to agricultural run-off and contributes to the damage of freshwater ecosystems (Mitchel, 2004). (Riley, 2017) states that run-off from agriculture is the main source of the increase in phosphorous levels.


The Canadian government has already tried to mitigate these effects by implementing regulatory instruments. The federal Fisheries Act was put in place to try and prohibit the distribution of harmful substances into freshwaters (Mitchel, 2004). However, there is little monitoring of this policy and the government has little tools and ways of holding accountability (Mitchel, 2004). The commissioner states that there needs to be more effective policies put in place in order to counteract these increasing trends and that partnerships between province and local agencies is needed to better the health of the watersheds (Riley, 2017). Implementing constraints on the nutrient pollution due to anthropogenic activities is needed in order to decrease the algal blooms (Larsson et al, 2017). This would be a challenging process however and would rely on a collaboration between all governmental frameworks. Legislation and policy would have to be based in scientific research and include individual communities to participate in the changes needed to reduce nutrient contamination (Mitchel, 2004).


The news article does a good job of explaining how and why these processes are bad but does little in way of offering any solutions. It appears that a review of regulatory instruments is needed in order to mitigate against the affects that phosphorous is having on the growth of algal blooms. The application of these policies will hopefully decrease the contamination and start to reduce the scale of the algal blooms. However, tools that can hold people accountable need to researched and also further mechanisms of policy implementation.








Knights, D., Parks, K. C., Sawyer, A. H., David, C. H., Browning, T. N., Danner, K. M., & Wallace, C. D. (2017). Direct groundwater discharge and vulnerability to hidden nutrient loads along the great lakes coast of the united states. Journal of Hydrology, 554, 331-341.


Larsson, M. E., Ajani, P. A., Rubio, A. M., Guise, K., McPherson, R. G., Brett, S. J., . . . Doblin, M. A. (2017). Long-term perspective on the relationship between phytoplankton and nutrient concentrations in a southeastern australian estuary. Marine Pollution Bulletin, 114(1), 227-238.


Metroland Media. (2017). Province's Environment Commissioner warns of dangers of phosphorus in lakes. https://www.mykawartha.com/news-story/7762489-province-s-environment-commissioner-warns-of-dangers-of-phosphorus-in-lakes/


Mitchel, B. (2004). Resource and Environmental Management in Canada. Oxford University Press. Canada.



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