A few weeks ago I wrote about our own personal experience with blue-green algae collecting around our dock on the Winnipeg River, just downstream from the Lake of the Woods outlet. I contacted the local Ontario Ministry of the Environment and Climate Change and was pleased that they collected samples for analysis to determine if what we were seeing was in fact blue-green algae (cyanobacteria) or possibly more benign species.
The results have come back and it was Blue-green algae (cyanobacteria), more specifically microcystis. Further to that, the amount of microcystins in the sample was extremely high. “The algae sample collected at the shoreline (thick algae) returned a result of 3543.55 micrograms per litre (ug/l) total microcystins. This translates to 3.54355 milligrams per litre (mg/l). The maximum acceptable concentration for microcystin-LR in drinking water, from Ontario Regulation 169/03, is 1.5 ug/l. Microcystin-LR is a component of total microcystins. Sample RB924 was a sample of the thick algae near the shoreline.”A second sample was taken at the end of our dock close to our drinking water intake and although it did contain some algae, there were no microcystins found in it.
Apparently this high count of microcystin is the highest that two of the scientists have ever seen so it does merit further thought, not just for our local situation but for the broader situation. The water that flows past our dock ultimately ends up in Lake Winnipeg and it originated from Lake of the Woods. Last year I posted a blog about some research from Oregon State University and the University of North Carolina that documented the increasing toxicity found in some blue-green algae blooms. Our recent experience here on the Winnipeg River certainly is consistent with that research.
The algae samples taken from our shoreline are going to be tested further to analyze more specifically what microcystis species were present and I will report on that once the results are in.
To conclude though, there is no imminent threat from this particular algae as it passed by very quickly and there has been no evidence of it returning. As well, it was only a small area close to the shore that was affected.However, I hope that this information will serve as a red flag that we need to pay more attention to assessing the extent of the problem and ultimately to instating the measures that will decrease this threat.