Freshwater lakes lose oxygen due to global warming

Freshwater lakes lose oxygen due to global warming

Oxygen levels in freshwater lakes are falling faster than in the oceans, largely due to global warming, warns a study published in the journal “Nature” on Wednesday.

Researchers at the Rensselaer Polytechnic Institute, in the United States, have detected that oxygen in lakes located in temperate zones of the planet has decreased by 5.5% on the surface and 18.6% in deep waters since 1980.

While the loss of oxygen in the oceans has been documented in some detail, changes in oxygen concentrations in lakes are less well known due to the absence of detailed and sustained studies over time.

To try to fill that gap, biologist Kevin Rose and his research group have compiled oxygen measurements made in 393 temperate lakes, most of them in Europe and the United States, between 1941 and 2017.

From these data, they have determined that the oxygen decline is between two and nine times higher in these waters than that observed in the oceans.

The study authors believe that the lower concentration of the element on the surface of the lakes is due to the increase in water temperature.

In the depths, on the other hand, the effect responds to a “stratification” of the thermal layers of the lakes, as well as a loss of “clarity” of the waters.

All complex life depends on oxygen. It is the support system for aquatic feeding networks. If you start to lose oxygen, you are potentially going to lose species, “says Rose in a statement from her university.