Harmful Algae
Measures the number of water bodies with harmful algal blooms across Canada.

Getting data to report on this impact measure is a work in progress. This shared measurement system belongs to all members of the Our Living Water Network, so if you have any data or ideas to share with us on this measure, please send us an email at [email protected].


An overgrowth of harmful algae is primarily caused when excessive nutrients, especially phosphorus and nitrogen, enter the water causing these sometimes toxic substances to unnaturally thrive. Cases of harmful algae plague Canadian waterways every year. Blue-green algae is a particularly toxic form of algae and can have negative, life affecting impacts on aquatic systems, species and on human health. Algae blooms can have further impacts on recreational water use and on economic activities of the region.

Unfortunately, tracking cases of harmful algae blooms in Canadian waterways is no easy task. There are millions of water bodies across the country and some jurisdictions only take an action or support monitoring when blooms are ‘reported’, whereas others don’t maintain any list of harmful algae outbreaks at all. For example, in Ontario, Quebec and Nova Scotia, monitoring is triggered only when algae is reported; whereas, in British Columbia, Alberta, Manitoba, New Brunswick and Prince Edward Island there are blue-green algae monitoring programs of varying types. As can be seen, monitoring - when it does happen - is markedly different from province to province, making it difficult to aggregate results across Canada. As a result, there are likely many more algae blooms than what’s being reported or publicly available. More work needs to be done to determine how best to gather data for this impact measure in a meaningful way.

5-Year target: To establish a process for, and identify, an initial benchmark for this impact measure.

Last updated November 2017

Our Living Waters Network Members leading this conversation:

If you would like to be part of this conversation, email us at [email protected].

Note : Les données présentées ici proviennent de nos recherches exactes au meilleur de nos connaissances, compte tenu du temps et des ressources disponibles. On reconnaît qu'il puisse y avoir des erreurs. Ce système de mesure partagé appartient à tous les membres du réseau Nos eaux vitales. Donc, si vous avez des corrections à nous soumettre, ou des idées à partager quant à ce système, n’hésitez pas à nous envoyer un courriel. 

Harmful Algae|Measures the number of water bodies with harmful algal blooms across Canada.
Harmful Algae|Measures the number of water bodies with harmful algal blooms across Canada.
Imagine a Canada where all waters are in good health: