A recent study conducted by researchers from Manitoba and Saskatchewan reveals that a widely used fertilizer, crucial for global food production, can significantly harm almost half of the freshwater bodies in the Canadian Prairies. The study, led by Cale Gushulak, an assistant professor at the University of Manitoba, focused on the impact of urea and nitrogen-based fertilizers on aquatic ecosystems, an area with limited prior research.
The research involved adding urea to farm ponds in Saskatchewan to simulate the effects of agricultural fertilization in the southern Prairies. The results showed a substantial increase in microscopic algae growth, leading to oxygen depletion in the ponds, a phenomenon observed in damaged ecosystems like Lake Winnipeg. Gushulak emphasized that when fertilizers enter water bodies instead of remaining on land to support crop growth, severe water-quality losses occur, highlighting a global concern due to the widespread use of urea.
The study findings suggest that the excessive growth of algae, oxygen depletion, fish mortality, toxin exposure, and harmful algae blooms are pushing many freshwater bodies in the Prairies towards an “ecological tipping point.” Comparisons with similar water bodies in southern Saskatchewan indicated that nearly 50% of Prairie lakes, wetlands, and reservoirs could be degraded by long-term urea usage.
Gushulak also pointed out that agricultural regions in China and the United States face similar vulnerabilities to urea damage. However, he emphasized the importance of improving fertilizer technology, soil management, and crop practices to prevent fertilizers from entering water bodies rather than advocating for complete cessation of fertilizer use.
Asim Biswas, a professor at the University of Guelph, highlighted the study’s significance but cautioned against overstating urea’s impact, noting the interaction of urea with existing phosphorus levels in water bodies. Gushulak reiterated that while high phosphorus levels are essential for urea’s effects, many Prairie water bodies naturally have high phosphorus content, making them susceptible to urea-induced harm.
The study challenges the perception of Canada as a country abundant in freshwater, emphasizing the issues faced by water bodies due to urea contamination. Gushulak warned that if urea continues to pollute freshwater, it could lead to deteriorating water quality and increased water resource costs, especially as climate changes affect water availability in the Prairies.
In conclusion, the research sheds light on the urgent need to address the impact of fertilizers on water bodies to safeguard aquatic ecosystems and ensure sustainable water resources for future generations.