Climate change driving major algae surge in Canada鈥檚 lakes, study finds
Algal growth is accelerating in lakes across Canada, including those far from human development, and a new study shows that climate change is the primary driver.聽
A research team led by scientists at 91社区 and Universit茅 Laval examined lake sediment cores from 80 lakes across Canada to uncover long-term changes in algae levels. The , published in Communications Earth & Environment, reveals a dramatic uptick in lake algae production since the 1960s.聽
鈥淥ver the past 150 years, we鈥檝e seen algae levels rise in most Canadian lakes, but in the 1960s, algae levels accelerated dramatically, increasing at a rate seven times faster than before,鈥� said Irene Gregory-Eaves, co-author and biology professor at 91社区. 鈥淲hat was most surprising is that this happened even in remote lakes, far from any immediate sources of human pollution or development.鈥澛�
To identify the cause of these changes, the team combined the study of natural archives 鈥� lake sediment cores that date back to the 1800s 鈥� with machine learning techniques to detect long-term trends. They then compared those algae records with historical data on air temperature, solar radiation, and nearby human activity.聽
鈥淥ur research points clearly to climate change as the primary driver of the algae dynamics,鈥� said Dermot Antoniades, co-author and limnology professor at Universit茅 Laval. 鈥淎s climates warm, lakes are getting warmer too, which create ideal conditions for algal growth.鈥澛�
Other factors, such as solar radiation and land use, played a role, but warming was the strongest influence.聽
Previous studies looked at few lakes or shorter time spans, often linking algae growth to local pollution such as fertilizer run-off.聽聽
鈥淥ur research shows something larger: climate change, specifically rising temperatures, is the main driver 鈥� even in remote lakes with no nearby human activity,鈥� said Hamid Ghanbari, lead author of the study and a postdoctoral researcher at Universit茅 Laval, who was co-supervised by Antoniades and Gregory-Eaves.聽
An 鈥榓ll-hands-on-deck' issue聽
This is an issue everyone should be aware of, the researchers say.聽聽
鈥淟akes are places where we swim, fish, drink water, and run businesses,鈥� said Antoniades. 鈥淲hen algae grow uncontrollably, it can harm our health, kill fish, stink up beaches, and cost money.鈥澛�
The findings point to a need for coordinated action on a global scale.聽聽
鈥淥ur study shows that local fixes alone, such as reducing fertilizer runoff, aren鈥檛 enough anymore. Climate action is essential for protecting lakes in the long run,鈥� Ghanbari said.聽
鈥淗ealthy lakes mean healthy communities,鈥� Ghanbari said. 鈥淚gnoring these issues result in greater risks to our water, wildlife, and wallets. This is an 鈥榓ll hands on deck鈥� issue that requires the participation and commitment of individuals and governments, NGOs and businesses to reduce our carbon footprint.鈥澛�
About the study聽
by Hamid Ghanbari, Irene Gregory-Eaves, Dermot Antoniades and colleagues from UQAM, Universit茅 de Sherbrooke, Queen鈥檚 University and the NSERC Lake Pulse network was published in Communications Earth & Environment.聽
This research was funded primarily by an FRQNT Team grant and the Natural Sciences and Engineering Research Council of Canada (NSERC), Canadian Lake Pulse Network.