A Chinese government scientific research ship has completed an expedition in waters disputed by Vietnam and China in the South China Sea, according to Chinese state media and data from a ship-tracking platform.
The Tan Suo 2 left the Chinese port of Sanya on Feb. 2, sailing to waters west of the Paracel Islands — roughly 140 nautical miles off the coast of Da Nang in Vietnam — where Chinese state media says it collected biological samples, tested submersibles, and carried other such research until Feb. 9.
The ship’s voyage into Vietnam’s claimed exclusive economic zone is just the latest such research expedition by China, which claims most of the South China Sea for itself despite competing claims from five other Asian governments.
A U.S. warship challenged these claims on Wednesday, conducting a so-called freedom of navigation operation (FONOP) in the Spratly Islands, an area contested by China, Vietnam, the Philippines, Malaysia, Brunei, and Taiwan, the U.S. 7th Fleet said in a statement.
Notwithstanding the disputes over maritime and territorial claims, Chinese research vessels have consistently carried out research in the South China Sea and beyond – searching for natural resources, mapping the seabed, testing new technologies and conducting other types of scientific inquiry. At times, China’s research activities have drawn ire from neighboring countries.
For instance, in January the Jia Geng — a vessel owned and managed by Xiamen University — operated in Philippine waters without permission from the Philippine government, the Inquirer reported.
And in December 2020, Indonesia discovered a likely Chinese unmanned underwater vehicle near Selayar Island, which may have been collecting data to aid People’s Liberation Army (PLA) Navy submarines.
Coverage of the recent expedition by the Tan Suo 2 in Chinese state media indicates that the ship belongs to the Chinese Academy of Sciences Institute of Deep-sea Science and Engineering, a state-run research organization. Records reviewed by Radio Free Asia confirm that this institute owns and manages the Tan Suo 2.
The Tan Suo 2 reportedly carried a 60-person team from the Chinese Academy of Sciences and the “Deep Sea Warrior” manned submersible.
Automatic identification system (AIS) data reveals the Tan Suo 2 operating in waters disputed by China and Vietnam between Feb. 2 and Feb. 9. Credit: Data from MarineTraffic; analysis and annotation by RFA.
Over the course of the expedition, the researchers completed nine dives, collecting deep-sea biological, sedimentary, and water samples, which will be used to build a “South China Sea deep-sea biological resource bank” and study how organisms adapt to the deep-sea environment, state-run Xinhua news agency reported.
The researchers also carried out the first joint operation involving the “Deep Sea Warrior” and the “Luling” mobile multi-site submersible, the report said.
The Vietnamese government has not publicly commented on the Tan Suo 2’s recent expedition, which took place in an area that both China and Vietnam claim as part of their exclusive economic zones.
According to the United Nations Convention on the Law of the Sea (UNCLOS), coastal states have the right to regulate, authorize, and conduct scientific research in their exclusive economic zones, which typically extend up to 200 nautical miles from a country’s territorial sea baseline.
Over the past year, the Tan Suo 2 has repeatedly operated in the South China Sea and has ventured into the waters of the Pacific Ocean as well.
For example, the ship sailed down to an area southeast of the Paracel Islands in July 2020. And it finished at least four additional excursions into the South China Sea between the start of August and mid-October.
In December 2020, the Tan Suo 2 completed a 57-day expedition to the Mariana Trench. During this voyage, the ship deployed the “Deep Sea Warrior” for 32 dives, collecting a range of different biological and sedimentary samples, and carried other such activities, Xinhua reported.