The paper was led by Dr Qi Guan and Prof Kun Shi at the Nanjing Institute of Geography and Limnology (NIGLAS), part of the Chinese Academy of Sciences, with contributions from Tongji University [1]. Dissolved oxygen across the studied systems fell at an average rate of 0.045 milligrams per litre per decade over the study period [1][2].
Declining oxygen solubility driven by rising water temperatures was the primary factor, contributing 62.7% of the total deoxygenation. Heatwave events added 22.7%. Nutrient pollution from fertilisers and urban runoff, dam construction, and altered flow conditions made up the remainder, according to the paper [1][3].