LAC LA BICHE - As the white snow covers area lakes, it’s another colour associated with local water bodies that was the topic of a recent meeting about the local watershed.
Blue-green algae, and the increasing instances of its presence in local lakes, was discussed at the Nov. 28 open house of the Lac La Biche Watershed Management Plan.
While the blue-green algae – Cyanobacteria – blooms are an issue in many lakes every year, according to Rolf Vinebrooke, a professor in the Department of Biological Sciences at the University of Alberta, who was a guest speaker at the open house meeting, solutions exist to combat them, and this involves reducing phosphorus in the water.
Vinebrooke explained to community residents who attended the open house held in McArthur Place, that internal recycling of phosphorus in lakes occurs on an annual basis, and is promoted by warmer water temperatures and anoxia.
Lake anoxia is typically the result stemming from the disintegration of organic matter, which is made worse by high loads of nutrients.
“Once external loading of phosphorus has been significantly reduced or eliminated, legacy effects of past inputs will persist in lakes for likely decades,” Vinebrooke said.
Solutions
Vinebrooke says several potential physical, chemical and biological remediation strategies exist for reducing and eradicating algal blooms. He explained that these include aeration, the addition of phosphorus-binding reagents into bodies of water, and the manipulation of fish communities to enhance grazing pressure on algae.
In addition to these strategies for getting rid of algae, land management legislation aimed at zero nutrient loading into waterways and lake management policies are crucial, Vinebrooke explained to the audience.
“Lake management policies are also important, which must be grounded in scientific knowledge of the nutrient budgets and food-web structure in lakes plagued by algal blooms,” he said, explaining that this information is vital when planning how to mitigate these events, which often need to be tailored to individual lakes.
While he couldn’t provide specifics on which lakes in the Lakeland region are most impacted by algal blooms, Vinebrooke did say that since the area consists of more lakes than exist further south in Alberta, the total number of affected lakes across the Lakeland region is likely greater than in those other areas of the province.
Fiona Gregory, a remote sensing specialist with the Alberta Biodiversity Monitoring Institute (ABMI) at the University of Alberta was also part of the watershed meeting’s conversation on algae blooms. She explained that the key limiting nutrient for algal blooms is phosphorus. Therefore, she explained, the main key to combating algal blooms lies in controlling external sources of excess phosphorus that are entering lakes.
Some of the external sources that contribute to algal blooms, she continued, could include sewage, storm runoff, lawn fertilizer, as well as runoff from agricultural lands such as fertilizer and animal waste.
“The agricultural runoff is particularly challenging to control since it is a non-point source,” Gregory told Lakeland This Week, adding that that natural sources such as rotting vegetation and dissolved minerals also play a role in algal blooms.
These blooms are more prevalent in Alberta lakes-including those in the Lakeland region-due to the sedimentary nature of provincial bodies of water.
“Alberta lakes are already susceptible to algal blooms because of our sedimentary glacial geology which is rich in nutrients, and the fact that even our larger lakes such as Lac la Biche tend to be quite shallow and warm, in comparison to Canadian Shield lakes in Ontario, for example,” she said.
Some improvements
While cleaning up and eliminating algal blooms is challenging, according to Gregory, other Canadian lakes-including Lake Erie-have seen considerable improvement.
“Getting phosphorus out of detergent was historically a big win for water quality, but now intensification of fertilizer use and feedlots is probably the biggest contributor to lake eutrophication overall,” she said.
During 2024, Alberta Health Services (AHS) issued 34 advisories for Cyanobacteriain provincial lakes, including Lac La Biche Lake and Kewehin Lake in the Municipal District of Bonnyville region.
During the past summer, there were also water quality advisories put in place for McGrane Beach, Golden Sands Beach, and Plamondon Whitesands Beach, all of which are on Lac La Biche Lake.
The waterhsed open house also highlighted issues about local fish populations, residential and industrial partnerships to enhance the environment and increased education programming. The topics of the open house will be part of continuing research and monitoring by municipal and provincial officials.
Lac La Biche County officials have held several discussions over the last year with agencies and research groups offering ideas to reduce and remove blue-green algae outbreaks from local waters. More on the topic is expected to be discussed in the coming months.
