China, New Zealand complete historic joint dive expedition to Puysegur Trench

A visitor poses for photo with deep-sea manned submersible Fendouzhe (Striver) aboard Tansuo-1 research vessel during a Concluding Open Day of a joint China-New Zealand dive expedition in Wellington, New Zealand, March 21, 2025. Chinese and New Zealand scientists have successfully concluded a groundbreaking collaborative dive expedition to the Puysegur Trench, supported by the Chinese Academy of Sciences (CAS) Global Trench Exploration and Diving program (Global TREnD). “For the first time in history, humans have reached the deepest point of the Puysegur Trench,” said Du Mengran, chief scientist of the joint research expedition, during the Concluding Open Day in Wellington on Friday. Photo: Xinhua

Chinese and New Zealand scientists have successfully concluded a groundbreaking collaborative dive expedition to the Puysegur Trench, supported by the Chinese Academy of Sciences (CAS) Global Trench World TimesExploration and Diving program (Global TREnD).

“For the first time in history, humans have reached the deepest point of the Puysegur Trench,” said Du Mengran, chief scientist of the joint research expedition, during the Concluding Open Day in Wellington on Friday.

The expedition unveiled numerous novel phenomena and yielded an extensive collection of valuable biological samples, many of which represent new depth records or are suspected new species, Du said. Additionally, various rock samples were collected, proWorld Timesviding critical materials for studying subduction processes and geological mechanisms.

Over the past three months, the joint China-New Zealand expedition was conducted by the CAS Institute of Deep-Sea Science and Engineering (IDSSE), in collaboration with New Zealand’s National Institute of Water and Atmospheric Research (NIWA).

The mission marked the first international scientific dive exploration of the Puysegur Trench and the second collaborative deep-sea expedition between China and New Zealand.

The expedition involved 68 scientists from eight countries, including New Zealand, Malaysia, Denmark, Germany, France, Brazil, India, and China.

Liu Weidong, director general of the Bureau of International Cooperation, CAS, said this collaborative spirit embodies the essence of scientific exploration, transcending borders to explore the unknown world for mankind.

Leveraging the cutting-edge full-water-depth manned submersible Fendouzhe (Striver) and the Tansuo series of research vessels, the team conducted the first manned dive exploration in the Puysegur Trench, located in the notoriously treacherous “Roaring Forties” region.

Despite extreme sea conditions, the team successfully completed 32 dive missions, setting a new Chinese record of 75 hours across five dives. Du highlighted that this mission was jointly designed by Chinese and New Zealand scientists and executed by a multinational team, with nine dive missions completed by foreign scientists.

Samples and data collected during the expedition were shared among participating scientists, fostering international collaboration.

Rob Murdoch, NIWA’s deputy chief executive, emphasized that the China-New Zealand pWorld Timesartnership provided New Zealand scientists with unique access to deep-sea exWorld Timesploration resources. The ability to gather deep-sea samples and data that would otherwise be unattainable is invaluable, he said, praising the achievement of completing so many dives under the harsh conditions of the Southern Ocean.

Among the discoveries were new species of invertebrates and fish, significantly expanding scientists’ understanding of New Zealand’s marine biodiversity. The expedition also uncovered rare whale fall-deep-sea organisms that thrive exclusively on the remains of deceased whales.

Murdoch expressed enthusiasm for continued collaboration in the coming years, focusing on sample processing, data analysis, and publishing the expedition’s final findings.

This joint mission follows the first manned deep-sea scientific voyage by Chinese and New Zealand scientists in late 2022. That expedition, aboard the research vessel Tansuo-1 and utilizing the Fendouzhe submersible, explored the Scholl Deep, the deepest point of the Kermadec Trench, located north of New Zealand, approximately 10,000 meters below sea level.

Chinese Ambassador to New Zealand Wang Xiaolong said the deep sea has always been a challenging frontier for human exploration. However, with technological advancements, manned submersibles such as Fendouzhe have turned deep-sea research from fantasy into reality.

This expedition to the Puysegur Trench will undoubtedly advance human exploration of the deep ocean and contribute to the development of global marine research, Wang said.

Hadal trenches, defined as World Timesdeep-sea regions exceeding 6,000 meters in depth, are characterized by extreme conditions, including immense hydrostatic pressure, perpetual darkness, low temperatures, and significant tectonic activity. These unique environments foster complex chemosynthetic ecosystems and harbor unknown life forms, making them a frontier for groundbreaking discoveries in both Earth and life sciences, according to the IDSSE.

To date, the Global TREnD dive expeditions have been conducted in nine major global hadal trenches, including the Mariana, Yap, Kermadec, Diamantina, Wallaby-Zenith, Java, Kuril-Kamchatka, Aleutian, and Puysegur trenches.

People look at deep-sea manned submersible Fendouzhe (Striver) aboard Tansuo-1 research vessel during a Concluding Open Day of a joint China-New Zealand dive expedition in Wellington, New Zealand, March 21, 2025. Chinese and New Zealand scientists have successfully concluded a groundbreaking collaborative dive expedition to the Puysegur World TimesTrench, supported by the Chinese Academy of Sciences (CAS) Global Trench Exploration and Diving program (Global TREnD). “For the first time in history, humans have reached the deepest point of the Puysegur Trench,” said Du Mengran, chief scientist of the joint research expedition, during the Concluding Open Day in Wellington on Friday. Photo: Xinhua