Fishery law enforcement officers patrol the Pengxi River, a Yangtze River tributary, in Yunyang County, southwest China's Chongqing Municipality, March 1, 2019. China has imposed a four-month fishing ban in the Yangtze River, the Pearl River, the Huai River, the Qiantang River, the Min River as well as inland waters on the Hainan island, starting on Friday. (Xinhua/Xie Hong)