
Beware the green monster
When summer gets too hot to handle (not something that’s been a huge problem so far this year), my favourite path to refreshment is a plunge into the cool St. Lawrence. I was in for the first time last weekend, and it felt wonderful. But I worry about invaders that are upsetting the balance.
Of the many things troubling Canada’s waters, algae is a blooming problem. Excess nutrients from many sources is finding its way into the water. According to Ontario’s Ministry of the Environment, “…any increase in phosphorus in the lake will increase the quantity of algae that can grow. High levels of phosphorus can lead to algal blooms and in some cases affect the habitat of cold water fish such as lake trout.” Why does that matter? Well, according to a ministry fact sheet, excess algae means lower oxygen content. And lower oxygen content means things living in the lake end up dead, particularly trout, but lots of other forms of life as well. In the worst-case scenario, the algae load the water with bacteria, making it undrinkable.
The ministry offers an opportunity for landowners to test for phosphorus levels in their area waterways. Click here for more information.
You can contribute in other ways as well: If you’re buying fertilizer, look for a low or zero-phosphorus option, so that nutrients that wash out of the soil don’t end up in a waterway. (I live in the middle of Toronto, but I can see that the storm water system could take material from my garden straight to Lake Ontario.) Bags of fertilizer have a series of three numbers printed on it to indicate nutrient level. The numbers are the percentage nutrient content of nitrogen, phosphorous, and potassium, in that order. If the package says 21-0-17, for example, the phosphorus count is zero. Beyond fertilizer, stick to phosphate-free detergents — both for your body and for washing things like cars and dishes — and ensure that your cottage septic system is contained.
Minnesota passed laws in 2002 to control the level of phosphorus in commercially available fertilizer, and apparently Maine, parts of Michigan, Wisconsin, Maryland and Manitoba have followed suit.
Have you noticed anything upsetting the water in your area?