WHY IS THE LAKE GREEN?
We have a nutrient problem; when summer time is here, that means trips to the lake. Boating, swimming, fishing, or even just plain relaxing. Lakes and parks are a wonderful place to spend time, so why is it that our favorite lakes can be that not-so-beautiful clear blue in the summer months? The answer is algae. So, what is algae anyway?
The term “Algae” refers to a broad scope of organisms. Algae can range from the microscopic single celled organisms that can be floating in a lake, to “seaweed” that is found floating in clumps on the surface. These tiny little micro-organisms live off of the nutrients, like nitrogen and phosphorus, in the water and use the sunlight to photosynthesize, much like the plants and trees do above water. These little organisms contain large amounts of “chlorophyll.”, which is a pigment that makes all plants green. So it’s algae that is making our lakes mucky and unpleasantly green. But, this doesn’t happen in other lakes so why is it happening in ours?
An algal bloom happens when the number of algae organisms in the lake increase dramatically turning clear water green. These algae are able to reproduce because there is an excess of nutrients found in the water. These nutrients, phosphorous and nitrogen, tend to collect in lakes. In the summer the algae have both the excess nutrients and the excess sun needed to bloom in large numbers.
Is algae a bad thing? Algal blooms are a natural thing indeed, but when they get too large or persist year after year they can damage the ecosystem of the lake, and be harmful to its inhabitants, and its users. When a lake has particularly large algal bloom, and the water becomes very murky and green, bad things start to happen.
Algae live very short little lives, and when they die they begin to decay. This decaying process uses up the dissolved oxygen found in the water. If the algal bloom is particularly large, the amount of decaying algae increases as well, and this can add up to big trouble. Fish and other underwater critters use this dissolved oxygen to breathe, and if it is all used up by decaying algae they can suffocate. Blue green algae produce toxins that can also make pets and humans sick.
Who is the LQWS? The Lower Qu’Appelle Watershed Stewards (LQWS) is an independent, non-profit organization committed to protecting our water source in the Lower Qu’Appelle River Watershed. Our Vision is a long term, stable, high-quality water supply for people and for the environment. Source water protection and safe drinking water is our key focus. According to our “State of the Watershed” Report, the Lower Qu’Appelle River is highly stressed
According to First Nations accounts and researchers at the University of Regina and Dr. Peter Leavitt, the Qu’Appelle used to have a lot less algae. Leavitt’s team–part of the country’s longest-running fresh water research program, apart from the Government of Canada–has monitored water from our lakes every two weeks from June 1994 to the present, as well as 100 other lakes from within Treaty Four territory. Their findings indicate that it’s not just the Qu’Appelle lakes that are being adversely impacted by green algae. Of the 100 lakes tested, all had water that could not be consumed without treatment. At a Treaty 4 gathering, he said ““It took us a hundred years to pollute Pasqua Lake. We will not return it to its original condition in a few years. It’s going to take decades,” said Leavitt.
Now new research by scientists at the University of Regina’s Institute of Environmental Change and Society shows that global warming is increasing levels of toxic algae detrimental to human health. Dr. Leavitt explains that urban growth and intensive agricultural activities increases pollution of freshwaters with nutrients, which increase growth of harmful algae known to produce potent water-borne toxins.
How can we implement change? Through education, science, pilot projects and maybe even lobbying our governments for change.
Stand by for part 2:
We have a nutrient problem
