Authored by Emily Ury and Nandita Basu on November 11, 2022
Wetlands are often referred to as the earth’s liver, because much like the liver does in the body, wetlands remove toxic substances and pollutants from the environment. But how do wetlands improve water quality?
Wetlands are like sponges. They soak up flood waters, holding onto them in their soils just long enough for plants, insects, and the microorganisms that live in wetlands to get to work. All of these living organisms act as the first line of defense against pollution. Wetland plants take up excess nutrients, like nitrogen and phosphorus, from lawn fertilizer and animal waste, preventing it from reaching our streams and lakes where it can lead to harmful algal blooms. Plants can also take up heavy metals, like cadmium and copper, known for their deleterious health effects. Microbes can break down organic pollutants like pesticides, which can be potent neurotoxins. Finally, many of the toxic chemicals that enter wetlands simply get trapped and settle into the soil, where they get buried. This trapping of harmful substances effectively protects plants and animals (including people!) from exposure.
When we consider how many different kinds of harmful chemicals and pollutants we emit into the environment, it is no wonder why wetlands are so important. In conventional water treatment plants, each pollutant might require special treatment steps in order to be effectively removed, and ultimately, these costs add up.
But, just how much is the cost of conventional water treatment? Are wetlands really that valuable? In a word, YES. The money value of wetlands cannot be understated. The tax burden of maintaining clean water without the help of existing wetlands would be felt by everyone. It is estimated that a small wetland of only one hectare (about the size of a football field), saves about $1,000 in water treatment costs every year, adding up to billions of dollars in Ontario alone. These small wetlands are the most threatened by development and urban sprawl, but it is essential that we maintain a healthy distribution of small wetlands throughout the province to protect us from harmful water contamination.
Another way of thinking about the impact of wetland loss, is to consider the downstream effects. When you replace a wetland in an urban or suburban neighborhood, you might not notice the deterioration of your own water quality, but the consequences travel downstream. Think about how often we experience beach closures in our lakes due to harmful algal blooms. The problem of contamination in our lakes will continue to grow, if we lose the purifying power of our urban and agricultural wetlands.
Southern Ontario has already lost over 70% of its natural wetlands, losing the rest could have devastating consequences. A study conducted in the Mississippi River Basin in the US showed that the loss of existing wetlands would double the nutrient load to the Gulf of Mexico, thus aggravating the massive hypoxia and algal bloom challenges that currently exists in the region. The cost of reducing the phosphorus pollution that is currently causing the same water quality problems in the Great Lakes is estimated to be $3 billion CAD. This cost, and the cost to our tax payers, will only increase if the destruction of wetlands is allowed to continue in Ontario.
Loss of wetlands in Ontario will be felt by everyone, either through our wallets, as taxes are raised to compensate for rising water treatment costs, or through our declining health from exposure to contaminated water. Let’s not let this be our fate.
Take action: contact your MPP or submit a comment to the standing committee reviewing Bill 23 by midnight November 17, 2022. Read more about the proposed legislation changes and why you should act!