This past September the Canadian Audubon Society released a study predicting that our children and grandchildren may not hear the call of the loon around our lakes.
As lakefront owners talk, people with long experience on the lakes tell stories of
- how many more frogs, fish, crayfish etc. there used to be
- how the lake water was so much clearer and
- how algae and weed growth are increasing
Many wonder if the things they take for granted are threatened.
Let’s explore one issue – Algae and Blue Green Algae Blooms in order to help us understand how things have changed.
Here is a chart from the MOE showing the rapid increase in Algal Blooms.
We used to think that protecting our lakes from algae and most importantly blue/green algal blooms was simple. If we kept our phosphorous levels below a certain range then we were safe. But over the last few years algae blooms have occurred more and more frequently in lakes that previously were thought to have safe levels of phosphorous. The best lake health scientists are starting to understand that our lakes are being affected by what’s called – Multiple Stressors.
What are those stressors and how do they relate to increasing danger of algal blooms?
Decrease in Calcium levels – is leading to fewer Daphnia and less healthy Daphnia in our lakes. These tiny creatures are known as the living lawn mower for their ability to eat algae and thus keep algae levels under control.
Increased invasive species – Example – in Lake Nippising which used to have the 5th largest fresh water fish population in Canada, the invasion of spiny water fleas has had very serious effects. As these fleas die they use up incredible quantities of oxygen in the lake water. As the oxygen levels drop, the phosphorous that has built up in the sediment on the bottom of the lake (from our septic systems) is released into the water column - increasing algae growth. The fishery is Lake Nippising is now virtually destroyed.
Increasing Lake Temperatures – due to Climate Change our lakes are 1-2 degrees warmer than they were a decade ago – warmer water holds less oxygen and increases algae growth.
Scientists are looking at many more possible stressors and state that they do not have all the answers they would like to have – more research is needed. (One scary piece of info is that the Dorset Environmental Science Centre is one of the key places where this research takes place – yet their staff has been cut by almost 2/3 in the last decade)
So will we continue to hear the call of the loon? – Perhaps it’s up to us.
Author Paul MacInnes, Chair of the C.H.A., is a Passionate Lake Protector