Mini-Biofilia Environmental Project

As outlined in our summer newsletter we funded with the municipality a “mini-Biofilia” environmental study this past season. Below is a synopsis of the preliminary findings from the two scientists. A complete report is here.

This year was unusual for the lake environmentally due to the pandemic – less boat traffic, less people = less septic activity, etc. This may have resulted in lower levels of indicators of environmental degradation than previous measurements (see details below). Perhaps one positive result of the pandemic! Over the long-term however, climate change, warmer air and water temperature, bigger boats, more and bigger cottages, etc. affect phytoplankton (microscopic algae) and the transparency of the water (again see details below) and result in environmental degradation.

Phosphorus in the water (naturally occurring but greatly increased by human activity) directly influences the growth of phytoplankton. Measurements so far have indicated a 20% decrease in phosphorus compared to the previous 2 years – a positive result perhaps due to decreases in human activity.

Periphyton (the algae on the lake bottom close to shore) was measured by a team of six volunteer teens over the summer and compared to the measurements taken in 2009 in the Biofilia study. Again, the results were positive – an approximately 33% decrease in the thickness of the periphyton (or algae) was observed. The pandemic…??

Independent of this study Jean-Louis has noticed a marked decrease in visibility over the last three years at the thermocline (the area where water temperature changes from warmish to coldish – around 5-7 metres deep). The water becomes very opaque. This year it was less apparent as the season progressed. (Good news….again, the pandemic??)

Cyanobacteria (blue-green algae) are a commonly occurring and almost always benign alga in lake water. Cyanobacteria were measured at the thermocline and found to be quite concentrated as were phosphorus levels. Testing revealed that there were almost zero toxins present and the water was drinkable (with filtration and boiling).

Results from this year, given pandemic related lack of human activity, were mostly quite positive. This may be an aberration and your association is seriously considering repeating portions of this study next year or later when activity on Lac-des-Seize-Iles returns to normal.

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