False killer whales are seen in the South China Sea, July 18, 2020. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

A short-finned pilot whale is seen in the South China Sea, July 20, 2020. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Photo taken on July 24, 2020 shows sperm whales in the South China Sea. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Short-finned pilot whales are seen in the South China Sea, July 20, 2020. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Fraser's dolphins are seen in the South China Sea, July 20, 2020. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Photo taken on July 24, 2020 shows a sperm whale in the South China Sea. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Photo taken on July 24, 2020 shows a sperm whale in the South China Sea. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Aerial photo taken on July 24, 2020 shows a sperm whale in the South China Sea. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Photo taken on July 24, 2020 shows sperm whales in the South China Sea. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)

Researchers make observations during an expedition in the South China Sea, July 24, 2020. Chinese researchers have spotted 11 whale species in the South China Sea during a deep-sea scientific expedition, the Chinese Academy of Sciences said Tuesday. (Xinhua/Zhang Liyun)