An aerial drone photo shows short-finned pilot whales swimming in the waters east of Hainan Island, south China, July 5, 2024. A marine biodiversity expedition team has recently witnessed a large number of cetaceans in the waters east of Hainan Island, including short-finned pilot whales, Fraser's dolphins and rough-toothed dolphins. Among the cetacean species, many mother-child pairs have been spotted. (Xinhua/Zhang Liyun)