Altered greenhouse gas emissions in shallow lakes invaded by common carp (Cyprinus carpio)

Species invasions are among the most important environmental problems facing freshwater ecosystems this century, contributing to biodiversity loss and changes in ecosystem function. Freshwater lakes are an important component of the global carbon cycle and a key source of atmospheric greenhouse gases, yet the consequences of species invasions on gas emissions remain poorly understood. In this study, we analyzed greenhouse gas emissions from shallow lakes invaded by one of the world's most damaging invasive species, the common carp. We show that lakes with invasive carp had lower methane emissions despite increased eutrophication, contradicting the well-established assumption that methane emissions from lakes increase with nutrient levels and productivity. Lakes with carp had reduced sediment phosphorus concentrations, likely due to bioturbation, which correlated with lower methane emissions. Given the widespread and global nature of carp invasion, carp may have the potential to alter carbon and nutrient cycling at large scales.