The study found that some freshwater ecosystems have become more acidic with rising pCO2 (partial pressure of CO2). They also show in lab studies that increases in freshwater pCO2 can have detrimental effects on at least one keystone species, a tiny freshwater crustacean, leaving them less able to sense and defend themselves against predators. The findings suggest that increasing CO2 levels may be having widespread effects on freshwater ecosystems.
“Ocean acidification is often called the ‘climate change’s equally evil twin,’ and many current investigations describe tremendous effects of rising CO2 levels on marine ecosystems,” says Linda Weiss at Ruhr-University Bochum in Germany. “However, freshwater ecosystems have been largely overlooked. Our data indicate another pCO2 problem: pCO2-dependent freshwater acidification.”