Across the world, lakes are experiencing deoxygenation due to the climate crisis.
According to a study by the journal nature, long-term declines in dissolved oxygen concentrations in coastal and ocean waters have been linked to climate warming and human activity, but little is known about the changes in dissolved oxygen concentrations in lakes.
Researchers [of this study] observed temperatures across both surface water and deep waters levels, as well as the concentration of dissolved oxygen — the most important gas in aquatic ecosystems, writes The Hill.
“The new study provides a much-needed global overview of what happens in the limited freshwater stores of the planet – their health is a prime concern. Climate change, together with [agricultural pollution], threatens vulnerable freshwater systems, adding to the urgency to strongly cut emissions,” says Hans-Otto Poertner, a professor at the Alfred Wegener Institute in Germany.
Previous studies have shown falling oxygen levels in individual lakes, but this study is the first to look at so many lakes globally, as researchers gathered data from nearly 400 lakes in the United States, Canada, Europe, Asia and South America. The study found that in the past 40 years, oxygen levels have fallen nearly 19% in deep waters and 5% in surface waters, which is up to nine times faster than the oxygen loss in oceans, reported EcoWatch.
The deoxygenation of these lakes is hazardous for the lakes’ ecosystem by suffocating wildlife and changing the physical and chemical environment. Drinking water is also threatened when oxygen levels change.