Law enforcement officers from the fishery, public security and maritime sectors patrol the Yangtze River in east China's Jiangsu Province, 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/Su Yu)