New research out of McGill University has identified a potentially more efficient and cost-effective way to detect toxic blue-green algae blooms in lakes. Findings show that monitoring certain bacteria populations during active blooms is the key to indicating whether or not a bloom is toxic and should be reported to the public.
Toxic blue-green algae (or cyanobacteria) blooms are a natural phenomena that have existed for billions of years, but they’ve been exacerbated by human activity and a warming climate in recent decades.
The colourful, though often poisonous blooms are the result of an overabundance of nutrients, such as phosphorus and nitrate, which are found in fertilizers used in agriculture. At the same time, warmer lake temperatures brought on by climate change aid the chemical reactions necessary for a bloom to occur, making the phenomenon increasingly common, says Lara Jansen, the study’s lead researcher.
During a bloom, typically slate-coloured lakes turn a vibrant shade of green, due to the cyanobacteria’s light-harvesting pigments called phycobiliproteins. While eye-catching, if a bloom becomes toxic, by way of the cyanobacteria producing cyanotoxins, it can damage the environment and trigger mild irritation to severe illness among animals and humans.
“There are many ways that these toxins can affect people,” says Jansen. “There’s some toxins that impact your liver, some that impact you through the skin. There’s even some that impact the brain and your neurological function. So it can be a little bit scary.”
Jansen’s study was conducted using water samples collected from a series of lakes in the Cascade Mountains, where the researchers analyzed DNA extracted from various bacterioplankton to identify the different bacteria present in the lake. Among the bacterioplankton identified was a cyanotoxin degrader from the order Burkholderiales, which they consistently noted would appear in abundant populations during toxic blooms.
The conclusion was that the presence of Burkholderiales could thus potentially be used to assess toxicity of algae blooms. But Jansen adds that further studies would need to be conducted to confirm her findings.
Currently, other testing methods are expensive and laborious, but this study’s method efficiently uses DNA sequencing technology to assess whether further testing is needed to guide public safety communications.
“The ability for us to identify [bacterioplankton] has really come a long way, because genetic sequencing is a lot more cost effective than it used to be in years past,” says Jansen. “So this is an inexpensive way to go about things.”
Related Story The lake outside your cottage is ripe for drinking if you filter it—here’s how to assess your options
Related Story Could a virus be our weapon against harmful blue-green algae?
Related Story Who gets to decide how the lake will develop? Why cottagers on Muldrew Lakes are at-odds