A sperm whale is seen in the South China Sea, May 6, 2019. Chinese scientists conduct the world's first investigation of whales in the waters. Sperm whales, striped dolphins, and other rare cetaceans have been observed in the South China Sea, with a high probability of settled groups, according to the world's first investigation of whales in the waters, conducted by the Chinese Academy of Sciences. (Photo/China News Service)
A sperm whale is seen in the South China Sea, May 6, 2019. Chinese scientists conduct the world's first investigation of whales in the waters. Sperm whales, striped dolphins, and other rare cetaceans have been observed in the South China Sea, with a high probability of settled groups, according to the world's first investigation of whales in the waters, conducted by the Chinese Academy of Sciences. (Photo/China News Service)
Spotted dolphins are seen in the South China Sea, May 6, 2019. Chinese scientists conduct the world's first investigation of whales in the waters. Sperm whales, striped dolphins, and other rare cetaceans have been observed in the South China Sea, with a high probability of settled groups, according to the world's first investigation of whales in the waters, conducted by the Chinese Academy of Sciences. (Photo/China News Service)
A striped dolphins is seen in the South China Sea, May 6, 2019. Chinese scientists conduct the world's first investigation of whales in the waters. Sperm whales, striped dolphins, and other rare cetaceans have been observed in the South China Sea, with a high probability of settled groups, according to the world's first investigation of whales in the waters, conducted by the Chinese Academy of Sciences. (Photo/China News Service)