The Impact of Canadian Agriculture on Algal Blooms and Biodiversity


 |  Biodiversity/Conservation

While algal blooms sound like beautiful spring flowering events, these aquatic catastrophes routinely wreak havoc in Canada’s lakes, rivers, and seas. 

Algae, classified as eukaryotes, are similar to plants as they contain the energy-making green pigment chlorophyll. While there are many different types of algae, ranging from single-cell to complex seaweeds, all forms live in aquatic environments. 

Algae are an essential part of a healthy underwater ecosystem as they are a vital food source for many organisms. Their ability to grow and reproduce is highly impacted by nutrient availability, specifically nitrogen and phosphorus. Significant additions of these growth-limiting nutrients can flip a healthy water body into an aquatic dead zone within a short time frame. 

While our modern food system efficiently delivers vast quantities of goods to most Canadians, this sector has many hidden externalities. Externalities are defined as impacts that are not accounted for or reflected in a good’s or service’s cost.

For example, conventional agriculture produces unsustainable quantities of food for both animal and human consumption. This has significant environmental and health impacts. 

As a result, Canadian soils are exhausted and damaged from decades of intensive agricultural practices and maltreatment. Additions of synthetic nitrogen and phosphorous or livestock manure are now essential to meet yield demands each season. 

Unfortunately, these fertilizers are routinely overused and applied incorrectly, which results in them being washed and leached into nearby water bodies. Sadly, some farmers even dump leftover fertilizer or allow livestock to enter streams on their lands, dangerously contaminating the water. 

This influx of nitrogen and phosphorus tips the delicate nutrient balance within the aquatic system. Algae quickly grow, weaving a green carpet across the water surface, blocking sunlight and killing the plants below. 

Once the growth-limiting nutrients are used up, the algal bloom rapidly dies. Next, decomposers break down the dead algal cells, using up the water’s dissolved oxygen in the process. Eventually, other plants and animals are starved of oxygen and begin to die. This results in a food web collapse, and the water body is declared a dead zone

Our agri-food system’s influence on algal blooms 

As previously mentioned, the fertilizer abuse driving these ecological collapse events is propagated by inefficiencies in our food system. For example, animal agriculture requires vast quantities of feed for livestock, seeing more calories being fed to animals than their meat produces for humans. 

When considering the impact of a single beef steak, we must account for the land and water required to grow enough feed for the cow. We must consider the fertilizer and feces leached or dumped into nearby rivers. Finally, we must picture the mass fish deaths and dead zones tied to this meat. These negative externalities are not reflected in the cost of the steak as government bodies often subsidize the meat industry. 

Similar issues are seen with food waste in Canada. Again, extensive amounts of land, fertilizer, water, and fossil fuel-driven labour are required to put fruit and vegetables on our plates. 

Within this production line, crops are left in the ground and on trees, some rot in storage, and some are thrown out for aesthetic imperfections during sorting. The rest are left to rot in grocery stores and the refrigerators of Canadian families. 

Each year 58% of the food produced in Canada is wasted. This means we use a lot of damaging fertilizer, cause many algal blooms, and kill many plants and animals for food that is never eaten. 

What can we do? 

Algal blooms cause ecological collapse in rivers, lakes, and seas around Canada. They also threaten human health by poisoning drinking water, killing our marine food sources, and destroying recreational and cultural areas. 

Fortunately, there are solutions to combat algal blooms and inefficiencies in our food system. On a personal level, we can take small steps such as reducing our meat and dairy consumption. In addition, incorporating meal planning can help us reduce our food waste while also maintaining a healthy diet. 

Lastly, we must call on the Canadian government to make policy changes. We need a nationwide system monitoring food waste and policies that incentivize plant-based diets. In addition, cultivated meat has significantly less environmental impacts than standard slaughtered meat, so investment and regulation of amazing food technology can stop most agri-related algal blooms by removing the need to grow crops for livestock. 

Together we have the capacity to prevent algal blooms, biodiversity loss, environmental destruction, and human health issues while creating a food-secure system for all Canadians!