A recent study suggests that algae growth is on the rise in lakes across Canada, including remote ones, with climate change identified as the primary cause. Researchers from McGill University and Université Laval examined sediment cores from 80 lakes nationwide and observed an increase in algae levels in most lakes since the mid-1800s. The most notable discovery was a significant surge in algal growth since the 1960s, escalating sevenfold, attributed mainly to rising temperatures.
Apart from climate change, excess nitrogen and phosphorus from sources like animal manure, chemical fertilizers, stormwater, and wastewater can also fuel algal proliferation. While algae, bacteria, and phytoplankton play vital roles in the aquatic ecosystem, an overabundance of algae can have adverse effects. The study focused on overall algal growth and did not specifically address blooms.
Although some lakes naturally experience algae as part of their ecological balance, concerns arise if the heightened algae levels lead to abnormal growth. Excessive algae can endanger aquatic life and human health by compromising water quality, depleting oxygen levels, and producing harmful toxins, as seen in Lake Erie.
Daryl McGoldrick from Environment and Climate Change Canada emphasized that while increased algal growth doesn’t necessarily equate to more toxic blooms, it poses a threat to aquatic ecosystems, echoing the study’s findings on the impacts of warming.
Maëlle Tripon of Fondation Rivières noted a correlation between warmer temperatures and increased algae presence in lakes, emphasizing the need for both local and global efforts to address algal growth. While local actions like modifying farming practices and reducing impermeable urban surfaces are crucial, global policies to mitigate climate change are equally essential.
Lead researcher Hamid Ghanbari stressed the significance of individual choices in curbing algal growth, suggesting simple actions like minimizing fertilizer use and proper disposal of household chemicals can significantly benefit lake ecosystems.