We have been advised by representatives at the Ontario Ministry of Environment, Conservation and Parks (MECP) that the testing on the water sample taken from Brandy Lake on September 6th (and posted by the Health Unit on September 12th) has been completed. As we communicated in our last emails on September 15th and September 22nd , each sample for blue green algae has two tests; the first test to determine if it is blue green and the second to identify whether it is toxic or not. The toxicity test for the sample taken on Sept. 6th was identified this week as negative (i.e. non-toxic).
On Tuesday, September 24, MECP returned to Brandy Lake and took another sample from the Falkenburg Bay area of the lake. Blue green algae were identified this time as well, but the MECP did not consider this to be an algal bloom, but rather that algae were present in small quantities. The species of blue green algae that was identified in this sample is Aphanizomenon flos aquae. This species can be toxin-producing but does not always produce toxins. Even though the sample was not taken from water that was considered part of an algal bloom, it has been sent for toxicity testing. It is estimated that this will take at least three weeks before results are available. The labs that conduct this test are currently swamped because so many lakes in Ontario are reporting this year (i.e. we are not alone). It is important that we continue to take precautions until we know whether this second sample was toxic or not. While our lake has had blue green algae capable of producing toxins in it, Brandy Lake has never had a confirmed toxic algal bloom.
As an interesting side note, the species that was identified on September 24th is harvested around the world, and sold commercially as a dietary supplement. It has been used historically by cultures around the world as a source of protein.
In 2002-03, Brandy Lake had an algal bloom tested and identified as Aphanizomenon schindleri, a different species but the same genus. This species also can be toxin-producing but was not when it was sampled in 2003.
For those of you who have not been at the lake recently, we can confirm that the lake has cleared substantially, and there are no visual signs of algae in the water now.
We will keep you informed as new information becomes available to us.