A group of Southern Institute of Technology (SIT) students had a once-in-a-lifetime opportunity recently when they got up close to a Chinese deep-sea research submersible, which had just returned from its first exploration of the Puysegur Trench (6,300m), situated off the remote southwestern corner of Fiordland.
The group of 16 from SIT, made up of Master of Applied Management (MAM) students, management and staff, were invited along with other local guests to take part in the celebratory afternoon on the Tan Suo Yi Hao research vessel moored in Bluff Harbour, on Thursday February 20th, to mark the successful collaboration of the China – New Zealand Dive expedition to the Puysegur Trench.
Organised by the Consulate General of the People’s Republic of China in Christchurch, guests were welcomed with speeches, viewed a presentation and film on the expedition, which highlighted some of the discoveries to date, took in a tour of the vessel up to the bridge, and were treated to afternoon tea as well.
The presentation recognised that science and technology was an important part of the China – New Zealand friendship, with both countries possessing an abundance of marine assets. The project emphasised the valued partnership between New Zealand’s NIWA (National Institute of Water and Atmospheric Research) scientists and China’s IDSSE - Institute of Deep-Sea Science and Engineering. It provided the opportunity for Chinese and New Zealand scientists to work together “shoulder to shoulder”, creating mutual understanding and a deepening of the two countries relationship, and hoped that their exercise and teamwork would serve as an example of international co-operation.
The IDSSE initiated the Global Trench Exploration and Diving programme (2020-2030) to establish a platform for hadal-zone research collaboration, to foster alliances and networking through sharing equipment, technology and facilities. Located in oceanic trenches, the hadal zone is the deepest underwater environment - a water depth of 6,000 to 11,000 metres - and is the least explored habitat on earth. In 2022, the first combined China - New Zealand expedition took place in the Kermadec Trench, where the piloted, titanium-hulled submersible T545 – 1, took two scientists to Scholl Deep, 10km beneath the ocean’s surface.
For the first Puysegur expedition, two NIWA scientists came aboard the Tan Suo Yi Hao at Wellington (January 24-26) and the team of 60 (30 crew and 30 scientists) carried out surveying in the trench until February 20 before returning to Bluff. “There’s never been any seafloor sampling in the Puysegur Trench until this voyage,” said Dr Ashley Rowden, NIWA Principal Scientist - Marine Ecology; the expedition provided two firsts: the first survey ever carried out and the first biological samples taken from the trench.
Scientific objectives for the expedition included discovering unique fluid activities along fault lines where tectonic plates join and override, such as cold seeps and mud volcanoes; when and how subduction is initiated; geological features; biodiversity and species identification; anthropogenic pollutants and more. The trench also contains the deepest seep field in the Southern Ocean.
The trying weather conditions of the Southern Ocean present difficulties for any marine operations, due to the ‘roaring forties’, the strong westerly wind belt between 40° and 50° south, making the seawaters extremely turbulent. The team noted their work was very weather dependent; the wind and the waves making the expedition challenging. January provided the best weather window; operating in wind speeds of up to 36 knots and wave heights of up to 6.9 metres, 17 successful dives were completed, from depths of over 2,000 metres to 4,800 metres.
More than 1200 specimens were taken, including 36 invertebrates and two fish species. A highlight was the discovery of the Hadal Snailfish, a novel species, with the southern snailfish exhibiting purple/pink colours in contrast to its white Northern Hemisphere counterpart.
One of the finds which excited the scientists onboard was a sea pen meadow at over 5,000 metres deep. Although the meadow looks like plants, sea pens are animals. Research has shown they provide an important deep-sea habitat for certain species of fish larvae, protecting them from predators.
SIT student Kunpeng Huo said the Tan Suo Yi Hao research vessel visit was an exciting experience. Having spent his first year at SIT studying the Bachelor of Environmental Management before transferring to the MAM programme, he had some knowledge of deep-sea environments and found the presentation of the expedition findings interesting. “[It’s] very different to the surface. To survive [plants and animals] use chemosynthesis instead of photosynthesis.”
Chanchal Saini thought the visit was a good fit as a MAM student. “We study research and research proposals, international business, applied marketing, sustainable businesses.” It was her first time seeing a deep-sea research vessel. “It’s a totally new experience, and it’s great to be a part of it,” she said.
SIT Operations Lead, Daryl Haggerty attended with the SIT group and said it was a privilege for SIT students and staff to be provided with such a unique opportunity. “I would like to thank our hosts for extending the invitation, the informative afternoon and their warm hospitality.”
The scientific team stayed together on the Tan Suo Yi Hao for one further exploration. After taking on supplies they returned to the trench for more surveying and are due to return to China mid-to-late March.