By Mike Baker
A scientist hired by the Haliburton County Home Builders’ Association [HCHBA] to put together a report on the status of algal blooms across the county’s lakes says “there is no simple fix” to the problem that plagued some local waterways last year.
Put together by Dr. Melodie Lindsay, a specialist in biological sciences and microbiology, the report explains how toxic algal blooms form and what area residents and water stewards can do to limit their effects and eradicate the problem.
“Toxic algal bloom is a global problem brought on by a multitude of factors. There is no simple fix, and we are fortunate to not have experienced any noteworthy events thus far,” Dr. Lindsay wrote. “Prevention is a key strategic goal, both environmentally and economically, but this will only be achieved through proper water quality monitoring and using all the tools and local knowledge available to us to take rational and evidenced action.
The issue impacted several local lakes late in 2020. Little Glamor Lake in Highlands East tested positive for blue-green algae on Oct. 22, while Wenona Lake in Dysart el al, Bob Lake in Minden Hills and Gooderham Lake in Highlands East tested positive on Nov. 9. The outbreaks weren’t long, with all blooms reported to have completely dissipated by Nov. 14.
There was some concern locally as a result of the positive tests, with the issue debated at length at Haliburton County council on Nov. 25. Blue-green algae has the potential to be toxic to humans and animals.
Blooms fall into three general categories that vary in severity, according to information provided by the Haliburton, Kawartha, Pine Ridge District Health Unit. In category one, the water is cloudy, but translucent and no health effect is expected. In category two, the water colour changes and the algae may be clustered or in flakes, and may look like “pea puree.” In category three, the bloom is dense and may have a scum on top of the water, or look like a paint spill and can be easily swept by the wind.
When blue-green algae falls into category two or three, people are advised not to swim or use the water for drinking, cooking, rinsing foods or washing dishes. It’s also recommended that pets be prevented from entering or drinking the water.
Blue-green algae, or cyanobacteria as it is otherwise known, dates back 3.5 billion years, Dr. Lindsay says. There are over 2,000 different types. Most, if not all, photosynthesize, like plants, and produce oxygen. She estimates that blue-green algae are responsible for producing around 30 per cent of all oxygen on earth.
Dr. Lindsay says blue-green algae “have gotten a bad reputation” for their role in lake water quality over the years, but do have some benefits. Uncontaminated spores are a natural source of protein and vitamins, which may help to reduce fatigue. Products containing blue-green algae have been used to treat ailments such as high blood pressure and combat high cholesterol.
The report lists seven known triggers of algal blooms – stagnant water; high water temperatures, usually above 25 degrees Celsius; nutrient availability, in particular the ratio of nitrogen and phosphorus in water; high levels of dissolved carbon dioxide in water; long sunlight hours; sedimentation of other microscopic organisms; and light winds.
So, what can be done to prevent the formation of these blooms?
“Control of algal blooms is both difficult and controversial. It is safe to say there is no silver bullet and no one-size-fits-all approach,” Dr. Lindsay states. “A recent study found that one of the most important factors in successfully mitigating algal bloom is relying on local knowledge. Do we have leaky or aging septic systems? Are we nutrient loading our waters through intensive farming? Do we have storm runoff entering our lakes? Is our municipal sewage and stormwater system up to scratch?”
She added, “It’s easy to point fingers and shift blame, but it is impossible to make informed decisions without doing our homework.”
With that in mind, the next most important tool to understanding how, why and where blooms form is monitoring.
“Water quality monitoring will take us leaps and bounds closer to understanding the risk and true causes of algal bloom in Haliburton County,” Dr. Lindsay’s report says. “We should be testing water quality regularly, and specifically after storms, high boating traffic weekends, just after the lakes thaw, after leaf fall in autumn… Only then can be make effective changes for the better.”
Taking the information from the report, the HCHBA aims to reinforce the importance of proper scientific research when exploring new bylaws and policies that will affect future development across our community.