Protecting Our Freshwater Sources

This article looks at our freshwater and how maintaining the health of our rivers is an integral part of maintaining healthy oceans.

Written by: Thomas Tinmouth

June 8th-14th is designated as Rivers to Oceans Week, a time to remind us all of the importance of protecting the various water systems that feed into our oceans. This week we are reminded that local springs, creeks, streams, lakes, rivers, and wetlands are vital to the health of our Canadian oceans, which in turn are vital for our survival. Rivers to Oceans Week coincides with World Oceans Day on June 8th, appointed by the United Nations in 1992. World Oceans Day was put in place to inform people of the key role oceans play in our survival and create motivation and inspiration to treat oceans with care. Often we forget the impact that people living inland have on the oceans, mainly because we feel so far from the area, therefore removed from its problems. This is far from the truth. Just as populations inland have an impact on ocean degradation, they can also play a role in ocean restoration.

Canada’s Freshwater

Canada’s rivers discharge approximately 9% of the world’s renewable freshwater on an average annual basis. Ranking 4th in freshwater quantities worldwide with 2,902 cubic km, Canada would be considered a water-rich nation. Though 20% of the world’s freshwater is in Canada, only 7% is considered renewable. This means that 7% of this water is from rainfall and snowmelt that flows into Canadian rivers. The remaining water is non-renewable, meaning it collected hundreds to thousands of years ago when the area was much wetter. Overusing non-renewable water sources is dangerous as they can take hundreds of years to renew, and deplete quickly. Almost 9% of the country is covered in freshwater, from the many rivers, lakes, and various water systems. It is important to understand that this water does not just stay stagnant in Canada. The majority has a starting point and an ending point, coming from glaciers at higher altitudes, then flowing into rivers across Canada, and eventually into the ocean.

Figure 1 – Map highlighting the longest rivers in Canada.

There are over 8,500 rivers in Canada, including the Mackenzie River which is 4,241 km in length, the longest in the country. Approximately three-fourths of Canada’s land area is drained through rivers flowing into the Arctic Ocean and Hudson Bay. Refer to figure 1 for a visual representation of the longest rivers in Canada. We’ve now established that Canada has mass amounts of water flowing throughout its land, with a large majority flowing into the ocean. Though there are many positives that come with having this abundance of rivers and freshwater, this also means great responsibility to uphold its quality for the millions of people and species that directly rely on it. When it comes to water quality in the ocean, every single person on the planet is impacted. Humans, animals, and natural systems directly rely on quality ocean water for life, which is why it’s so important to treat the rivers that flow into the oceans with respect and care.

How do Actions Inland Degrade Oceans?


Runoff occurs when there is more water than the land can absorb, causing excess water to enter systems such as ponds, lakes, rivers, swamps, stormwater, and the ocean. Along the way this water picks up sediments and minerals, ending up in water systems. A small-scale example is water running off of your driveway and into stormwater drains near your home. The issue is runoff often brings with it harmful contaminants that are dangerous for the pond or river that it is entering. In the bigger picture, this is extremely harmful as these lakes and rivers that are receiving the runoff end up flowing into the ocean bringing along this contaminated water. Lawn care and agriculture are two common sources of runoff affecting our rivers and oceans.

#1 Lawn Care

Figure 2 – Lawn care runoff visual.

A common practice to increase lawn growth is to use fertilizers. The problem with fertilizers and other lawn care products other than water is that when it rains these chemicals are washed off of the lawn and into the surrounding environment. Most of these fertilizers are petroleum based which is toxic for aquatic and land life in the area. Another major issue is these sediments and chemicals contained in runoff are excess nutrients for the existing plant life in the lake. This increase in nutrients creates algal blooms, which block sunlight from entering the water, killing the grasses on the lake floor. These grasses are key for life in the lake as they provide food and shelter for the aquatic species. Lawns located around rivers and lakes will runoff into these water systems, contaminating the lake, which then may eventually flow into the ocean. This is a prime example of how ocean degradation can happen right from your own backyard, literally. This is an extremely harmful process as aquatic life is affected in the lake and eventually in the ocean.

There are two ways to avoid this issue of lawn runoff. The first is simple, just use water. Water is the only ingredient that is necessary for lawn growth. If this doesn’t work then laying some natural seed should do the trick. The second, and increasingly popular method for lawn care is to actually replace the grass with flowers, plants, and shrubs. Lawn-free front yards are becoming more popular as info around runoff and water usage becomes more prevalent. This is a sustainable switch as it builds a habitat for pollinators, eliminates runoff, and drastically reduces water usage. This is also a practical switch as less work goes into maintaining your front yard with the elimination of mowing and the stresses of maintaining the perfect lawn.

#2 Agriculture

Figure 3 – Algal blooms caused by agricultural runoff.

Runoff from agriculture works the same way as lawn care but usually is more harmful due to the abundance of chemicals picked up across the farm. Rain storms and snow melts are the two primary events that trigger runoff from farms. The most common causes of agricultural runoff are irresponsible pesticide usage and placement, irrigation of water and fertilizer, excessive plowing, and improper management of animal feeding. Often runoff from agriculture contains pesticides, sediment (soil particles), nutrients (phosphorus, nitrogen and potassium from fertilizers) and metals.

When this agricultural runoff enters bodies of water it is very harmful to the ecosystem. Similar to lawn care runoff, algal blooms become present, choking the plant life on the water bodies floor. This causes a ripple effect throughout the ecosystem affecting habitat, food sources, and reproductive methods. Dealing with this runoff problem can be difficult as there are point sources and non-point sources. A point source means you can locate the exact origin of where the runoff is entering the environment, while in a non-point source the origin cannot be easily identified. Runoff from farms entering rivers and lakes is extremely harmful to the immediate environment, but also to the ocean environment as these dangerous chemicals can be trapped in the water system flowing all the way to the ocean.

Here are three ways farmers can reduce their runoff:

Ensuring Year-Round Ground Cover

By planting perennial species farmers can prevent times of the year when there would be bare ground. Limiting the amount of bare ground reduces possible erosion and pathways to aquatic systems.

Planting Field Buffers

Planting trees, shrubs, and grasses along the edges of farmland can reduce the amount of runoff entering the natural environment, and filter out some of the harmful chemicals. This alone is not an effective preventative measure, but compounded with other techniques can be an effective last line of defence.

Adopting Nutrient Management Techniques

By applying nutrients and fertilizers in the correct amounts, at the right time of year, and in the correct area of the farm, the risk of runoff can be reduced.

Plastic Pollution

Figure 4 – Great pacific garbage patch, located in the North Pacific ocean.

Plastic pollution is another major threat to the health of our oceans. Litter, inability to recycle and improper waste management lead the charge of why 8 million pieces of plastic enter the ocean each day, 5.25 trillion pieces are floating in the ocean right now, and 100% of baby sea turtles have plastic in their stomachs. Figure 4 shows the great pacific garbage patch which is a giant island of ocean garbage, mainly plastics, that is 1.6 million square km, larger than Texas.

Incomprehensible ocean plastic facts can be listed for pages, making it hard to wrap your head around just how we got to this point. This isn’t just plastics produced from places near the ocean, this is plastic coming from all areas of the world converging into one area. Rivers are one of the many ways that plastics find their way from inland to the oceans. Plastics are toxic and choking hazards for aquatic life with 1 million seabirds and 100,000 marine animals dying from plastic pollution every year. When these plastics enter and sit in the water, they begin to slowly break down releasing microplastics which are smaller than 5mm in size. This makes it very easy for marine life to ingest these microplastics while they are swimming. It is estimated that 1 in 3 fish caught for human consumption contains plastic.

There are two actions that humans can take to help solve this problem. First, do not litter! Abstaining from littering is not good enough, rather when it is necessary to use plastic, make sure it is disposed of in the proper waste receptacle. Secondly, reduce or eliminate your consumption of single-use plastics. There are so many alternatives to single-use plastics that just take remembering and effort. Things like reusable water bottles, reusable bags, reusable containers, and reusable masks are simple life changes that everyone can make. They seem small, but they do make a difference, especially when multiplied around the world. 

For a system that allows us to breathe, provides food, and reduces the speed of climate change, we really do not treat the oceans with the respect that is deserved. We actually treat it more like a dumping ground. Oceans are the final destinations for our waste, and if we do not change our ways soon, we will slowly lose this invaluable system necessary for our survival. Beyond what the ocean provides for us, there is also the fact that this is a living breathing system with intrinsic value. Yes, it provides for us, which is definitely a motivating factor to act, but what about protecting it simply because it is alive? A perfect system that we are destroying. Maybe its beauty is beyond our capabilities to fully grasp. It is clear that something needs to be done, and we know what changes to make, now it is time to act.

Interested in learning more about our oceans? Find more articles here.

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