The Canadian Journal of Fisheries and Aquatic Sciences (CJFAS) has selected a paper lead by Queen’s National Scholar and researcher Diane Orihel as Editor’s Choice for 2017, an honour that highlights articles of particularly high caliber and topical importance, in recognition of her team’s national study of nutrients that feed algal blooms in Canadian lakes. Algal blooms – the blue-green scums visible on nutrient-polluted lakes – negatively affect not only recreational activities like swimming and fishing, but can put drinking water, property values, wildlife, and human health at risk.

“We looked at all of the national data on phosphorous release from sediments of Canadian freshwater ecosystems and saw how important paying attention to the bigger picture can be,” says Dr. Orihel (Environmental Studies, Biology). “I think our research will help us better manage our lakes and wetlands so all Canadians can feel safe to enjoy them.”

Dr. Orihel’s team investigated a process in Canada’s aquatic ecosystems: the recycling of phosphorus between sediments at the bottom of lakes and overlying water. Algae thrives on phosphorous so as it is released from lakebeds harmful accumulations of algae, called blooms, are more likely to form. Across the country tens or even hundreds of millions of dollars are invested every year to manage nutrient pollution – but in some lakes – legacy effects from nutrients deposited years ago can linger and delay recovery.

“Our main goal was to better understand where, when, and why this process occurs so that we can make improvements to how algal blooms are managed and develop realistic goals for lake restoration,” explained Dr. Orihel. “We found that phosphorus release from sediments was a common phenomenon in Canadian fresh waters, but that rates of this process varied dramatically from lake to lake.”

Major case studies featured in the article include Lake Simcoe, Lake Winnipeg, Lake of the Woods, Lake Erie, Lake Champlain, Cootes Paradise, and Lake Diefenbaker.

Prairie lakes in Manitoba, Saskatchewan and Alberta were shown to have the highest rates of phosphorous release, while the lowest rates were found in northern Ontario and the Maritimes.

“We found that oxygen levels, pH balance, nutrient status all affected the rate of phosphorus release from sediments,” Dr. Orihel says. “Following this study, it will be important to examine how human impacts, such as climate change and fish farming, affect this process so we can better tailor our efforts to improve water quality.”

The take-home message for the public, according to Dr. Orihel is “we need to stop dumping phosphorus into our lakes, because it’s not only causing problems right now, but in many lakes, it continues to deteriorate water quality for our children and grandchildren”.

The article was published online today in the Canadian Journal of Fisheries and Aquatic Sciences (dx.doi.org/10.1139/cjfas-2016-0500).

Collaborators on the project included Helen Baulch (University of Saskatchewan), Nora Casson (University of Winnipeg), Rebecca North (University of Missouri), Chris Parsons (University of Waterloo), Dalila Seckar (Queen’s University), and Jason Venkiteswaran (Wilfrid Laurier University)