Dams, water reservoirs created by damming a river, may have more impact on the environment than previously thought.
According to researchers at the University of Waterloo and the Université libre de Bruxelles, almost one-fifth of organic carbon, traveling the world’s rivers, is trapped by dams acting as carbon dioxide sinks.
"Dams don't just have local environmental impacts. It's clear they play a key role in the global carbon cycle and therefore the Earth's climate," said Philippe Van Cappellen, a Canada Excellence Research Chair in Ecohydrology at Waterloo and the study's co-author. "For more accurate climate predictions, we need to better understand the impact of reservoirs."
Additionally, researchers found that dam construction slows the transport of nutrients such as phosphorus, nitrogen and silicon through river networks, thus impacting the quality of water delivered to wetlands, lakes, floodplains and coastal marine areas downstream.
"We're essentially increasing the number of artificial lakes every time we build a dam," said Taylor Maavara, lead author and a Ph.D student at Waterloo. "This changes the flow of water and the materials it carries, including nutrients and carbon."
The research appears in the Nature Communications.