Photo taken aboard the Chinese research vessel, "Shiyan 3," shows birds fly over the waters of the Makran Trench in the northern Indian Ocean, Jan. 16, 2018. (Xinhua/Zhang Jiansong)

Photo taken aboard the Chinese research vessel, "Shiyan 3," shows the sunset scenery above the waters of the Makran Trench in the northern Indian Ocean, Jan. 15, 2018. (Xinhua/Zhang Jiansong)

Photo taken aboard the Chinese research vessel, "Shiyan 3," shows dolphins in the waters of the Makran Trench in the northern Indian Ocean, Jan. 15, 2018. (Xinhua/Zhang Jiansong)