Freshwater Ecosystems: Small But Mighty

Learn more about the freshwater crisis and how you can be part of the solution.

Aquatic ecosystems are essential to the health of our planet, and protecting freshwater resources is critical for human populations and biodiversity. As a local Toronto organization on the edge of the Laurentian Great Lakes, it is important to acknowledge our connection to freshwater ecosystems as we increase waste literacy and reduce plastic pollution in our local ecosystems.

We interviewed members of our team to learn more about their perspectives on the topic, and here’s what they each had to say.

Why do we need to protect our freshwater? Who do we need to protect it for?

Eden: Healthy freshwater ecosystems, including groundwater, wetlands, streams, rivers, and lakes, provide life-sustaining services to people and the planet. We call these ecosystem services, which refer to any positive benefit that biodiversity or ecosystems provide to society. These services can be direct or indirect, small or large, and are generally grouped into four broad categories: provisioning, regulatory, cultural and supporting. For example, freshwater ecosystems offer us water for drinking (provisioning), flood protection (regulatory), places for recreation and tourism (cultural), and have an integral role in nutrient cycling (supporting). These services, together with many more, make life on Earth possible and meaningful. This makes freshwater ecosystems worth protecting, for ourselves, our neighbours, and future generations – of all living things.

Markelle: Freshwater is crucial to the survival of many organisms including humans. However, only 2.3% of Earth’s water is freshwater, within which 9.5% of Earth’s species diversity resides. These biodiverse bodies of water are a pillar of food webs, supporting terrestrial organisms as well. As for humans, freshwater provides us with natural resources, energy, transportation and leisure. We need to protect the little freshwater our planet has for wildlife, humans, and future generations.

Alana: Water circulates continuously through the earth’s ocean, atmosphere and land in a system known as the water cycle, and without it there would be no life on earth. Mostly all of the water used in our homes and businesses comes from freshwater. While about 70% of the earth is covered by water, nearly 97% of this is saline and less than 3% is freshwater. Of this freshwater, less than 1% is easily accessible for use by humans and other livings things. It is found in lakes, rivers, streams, wetlands. Further, the earth’s water is finite, meaning it does not increase or decrease, while the earth’s population continues to increase. Therefore, it is critical to manage and protect this precious resource so that we can continue to have clean and healthy freshwater ecosystems to sustain life on earth.

Angelia: Freshwater is essential for both animals and humans, for ecosystems, and for societal needs. Things like sanitation, household groundwater reliance, habitats, and regional economies would be placed in danger if these finite resources are continually contaminated. Not only should freshwater be protected for the citizens of today, but for future generations as well

Why is freshwater important to you (and us)? What are some ways freshwater is unique to Canada?

Eden: The Earth’s surface is about two-thirds water, but less than 3 percent of it is fresh. Of that, only 1 percent of freshwater is easily accessible; the rest is trapped in ice caps and glaciers or in deep groundwater reserves. Canada has 7% of the world’s renewable (or easily accessible) freshwater. That’s pretty significant considering our country is home to less than 1% of the global population. It seems that we have more than our fair share, which is why we are often considered a freshwater-rich country. With such a significant portion of the world’s renewable freshwater resource comes a great responsibility to protect it – a responsibility shared by all Canadians.   

Markelle: Of all countries, Canada has the fourth largest volume of available freshwater, and has the most annual renewable water resources per capita. Freshwater is an invaluable resource that many Canadians take for granted. Most Canadians do not have to think about how much water they consume or how much remains on a daily basis, as is necessary in freshwater-poor countries. The cleanliness of our freshwater is also deteriorating as pollutants accumulate in our water reserves, so our water consumption behaviour may soon change. However, it is important to acknowledge that not all communities in Canada have access to clean drinking water. Currently, there are 34 long-term drinking water advisories in effect in 29 communities, disproportionately impacting those that are Indigenous.

Alana: Freshwater is essential in our everyday lives. Freshwater ecosystems provide water for human, agricultural and industrial uses such as- drinking, cooking, and cleaning as well as growing crops, hydro-electricity, and transportation. Additionally, freshwater ecosystems provide a habitat for a vast proportion of wildlife and plants while also providing us with recreation, income and even flood prevention control. Canadians are very fortunate to live in a freshwater-rich nation that is a custodian to the third largest supply of annual renewable freshwater in the world. Canada is also known for having more lake area than any other country in the world.

Angelia: Canada is home to 20% of the world’s total freshwater resources, and 7% of the world’s renewable freshwater. Access to drinkable water is a huge privilege, where Canada has a high amount of freshwater per capita. When many tap water sources are drinkable, it’s easy for this liberty to slip our mind, which is concerning due to how freshwater is increasingly becoming limited as time passes. For me, the importance of clean water was apparent when I visited Beijing with my family, where I couldn’t even use the sink to brush my teeth as the water tasted so pungent. This led to an increased use of bottled water, which is an entirely other environmental concern within itself.

What is the freshwater crisis? For humans? For biodiversity?

Eden: Given the tiny fraction of freshwater on Earth that is easily accessible, and the integral role freshwater ecosystems play in sustaining life, it is of great concern that they are among the world’s most degraded and threatened ecosystems. Freshwater ecosystems are a biodiversity hotspot – covering a small fraction of Earth’s surface, they are home to an estimated 10% of all known species. Unfortunately, freshwater wildlife populations that are monitored have declined faster than those in the oceans or on land, by 81% on average between 1970 and 2012. What’s causing this freshwater crisis? There are many drivers, but some of the big ones include unsustainable water extraction and flow alteration, invasive species, pollution, over-harvesting of species, habitat loss and degradation, and a rapidly changing climate – all of which trace back to human activities. 

Markelle: We are in a global freshwater crisis resulting from past and current human disturbance. The impacts of contamination, invasive species, climate change, and other activities have led to the decline of water quality in our lakes, rivers and wetlands. These ecosystems are not as biodiverse or stable as they once were, and sensitive species have become threatened, endangered, and extirpated (locally extinct). For humans, the freshwater crisis means water and food is less secure and will impact large populations, beginning with marginalized communities.

Alana: As populations continue to grow, the world’s water resources are in crisis. According to the United Nations, in the last century water use has grown at more than twice the rate of population increase, and it is estimated that by 2025 approximately 1.8 billion people will live in water scarce regions. The challenge before us is how to effectively conserve, manage and share the water we still have. Furthermore, freshwater species are going extinct more rapidly than land or ocean species. Almost one-third of freshwater biodiversity face extinction and this will likely continue to worsen as our populations grow.

Angelia: Freshwater sources are growing limited in their availability as more and more sources are becoming polluted by man-made causes. In cases where salinity of freshwater habitats increases, the mortality of their aquatic species does as well. When the base of freshwater food web starts to die off, whether they be shrimp, mussels or insects, these intricate ecosystems will collapse, and lead to a loss in biodiversity. Animals are not the only concern; humans are impacted as well. A lack of access to freshwater leads to an increased exposure to waterborne diseases like cholera, and the water systems themselves are beginning to dry up and disappear due to rapid rates of pollution.

What’s so great about our Great Lakes and our local freshwater tributaries that feed into them?

Eden: Like 30% of all Canadians, I live in the Great Lakes Basin, specifically the Lake Ontario watershed. And, like 1 in 4 Canadians, I get my drinking water from the Great Lakes. And, like many Canadians, my work (well, my Ph.D. research) is made possible because of the Great Lakes. In short, my life, like millions of other people, is intricately linked to the Great Lakes, made better because of them, and would look wholly different if they didn’t exist. That makes them pretty special.

Markelle: Southern Ontario is Canada’s biodiversity hotspot due to the ample freshwater provided by the Great Lakes and its tributaries. This biodiversity is important for the stability of ecosystems and food webs as well as the evolution of organisms. We humans would not exist without biodiversity as it provides us with ecological life-support and sustains economic, scientific, cultural and recreational values. Many of us have a personal connection to Canada’s freshwater ecosystems, whether it is catching crayfishes as a kid, fishing or birdwatching. We all have our reasons and duty to protect our freshwater.

Alana: The Great Lakes Basin is one of the world’s largest connected freshwater ecosystems. It consists of Lake Superior, Lake Huron, Lake Michigan, Lake Ontario, Lake Erie and thousands of tributaries. Together, this system holds approximately one-fifth of the world’s fresh surface water. Additionally, the Great Lakes generates millions of jobs annually, supply drinking water to around 40 million North Americans, and is the water feedstock for an array of industries. This important watershed also supports a diverse freshwater ecosystem including more than 200 species at risk.

Angelia: The Great Lakes are home to native freshwater species, and when pollutants start to contaminate these homes, these species’ survival rates can begin to diminish. Even nonnative species, like the salmon used to reduce invasive herring, are stunted by the increasing salinity of the Great Lakes, which then results in a drop in their population. Additionally, the Great Lakes are sources of water for our cities and farms and are what millions of North Americans rely on for clean drinking water.

What is the state of the Great Lakes? And how are we and how can we protect them?

Eden: The Great Lakes Water Quality Agreement, first signed in 1972, is a written agreement between Canada and the United States that commits both countries to work together to restore and protect the waters of the Great Lakes. Under the agreement, every 3 years both countries must report on the state of the Great Lakes by assessing a suite of 9 indicators of ecosystem health. The last report was published in 2019. On a scale of good, fair, poor, to undetermined (status) and improving, unchanging, deteriorating, or underdetermined (trend), the Great Lakes basin was scored as fair and unchanging. Not bad, but not great. The report notes improvements in the reduction of toxic chemicals but highlights significant challenges remaining in terms of nutrient pollution and invasive species. We’re due for another report this year, so watch out for an update on the state of the Great Lakes.

Markelle: The state of the Great Lakes isn’t so great. The southern Great Lakes (Michigan, Erie and Ontario) are generally in poorer condition than the northern Great Lakes (Huron and Superior) due to their close proximity to large human populations and agriculture. Nonetheless, all the Great Lakes are in worse condition than they were a few centuries ago. For example, where land and water meet, wetlands serve as critical nursing and spawning habitats for many fishes, birds, mammals, invertebrates, amphibians, and reptiles. However, it is estimated that only 20-40% of the Great Lakes wetlands retain their pre-colonial structure and function. Not only has this greatly impacted the survival of numerous species, but it has also negatively impacted humans. Wetlands naturally filter water for contaminants, cycle nutrients, and mitigate flood damage which benefit both wildlife and humans. The best way we can protect wetlands, the Great Lakes and other freshwater is to prevent further contamination and habitat degradation. It was not until the mid-1900’s that we realized how our (settlers) actions negatively impact freshwater ecosystems and we are continuously trying to reverse our mistakes with little success. Learning from our past mistakes is necessary to protect the Great Lakes from further degradation and pollution.

Alana: While the Great Lakes are important to the world’s freshwater resources, the reality is Canada’s freshwater ecosystems are in trouble. From rivers to streams, lakes and wetlands, all are under threat from pollution, water overuse, habitat loss and sub-division, changes in flow, climate change and alien species. These threaten the health of Canada’s freshwater ecosystems and all living things that rely on them. Additionally, 60% of Canada’s 167 sub-watersheds are data deficient, meaning we don’t have an informed understanding of our total impact on this critical freshwater resource. While this is improving, much more work is needed to obtain data on basic freshwater health indicators so we can work towards a future where the Great Lakes, and all waters, are conserved.

Angelia: Chloride levels are rising in the Great Lakes as a result of human activity. Pollutants from things like dissolved road salts, water softeners, and fertilizer runoffs are increasingly placing these freshwater ecosystems in danger. It’s immensely difficult and costly to remove chloride from water, which is one of the reasons why we don’t use desalinated water from the ocean as a primary source of water. This means that the cause of these pollutants has to be stopped at the root. Educating the public should be one of the first steps, where widespread road salt use during the heavy winters can be reduced and regulated through conscious citizen and municipal changes.

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Freshwater ecosystems are extraordinary. They may be small compared to marine and terrestrial ecosystems, but wow, are they mighty. But, as we have learned, our freshwater ecosystems are in crisis, and the responsibility falls on us to turn the tide.