Scientists explore the deepest depths of the Kermadec Trench


A team of international researchers leaves Wellington this weekend to explore the bottom of the Kermadec Trench – one of the deepest places in the ocean.

RV Tangaroa in Wellington harbour, 2017 [Photo: Dave Allen]

The three-week expedition aboard NIWA’s flagship research vessel Tangaroa involves scientists from Denmark, Germany, the United Kingdom, Chile and New Zealand, who will investigate the biogeochemistry and biology at the bottom of the 10,000m deep trench.

Trenches represent some of the most remote and scarcely explored areas on Earth. The southernmost part of the Kermadec Trench begins about 120km off the coast of New Zealand, and extends northeast for 1500km. The team will deploy sophisticated cameras and instruments that will image and monitor conditions along the trench axis. 

Prof Ronnie N. Glud from University of Southern Denmark, who is leading the research project, says that one of the main challenges investigating the biogeochemistry, microbiology and fauna from great depth is that changes in pressure and temperature strongly affect the samples.

“Therefore, to obtain trustworthy insight on biogeochemical processing and microbial performance, we have to take measurements directly at the seabed and preserve microbial samples before they are returned to the surface.“

The science team has developed different autonomous instruments, that once released from the ship, sink to the bottom and conduct preprogrammed experiments and measurements. Once the mission has been completed the instrument returns to the surface with data and samples after 1-3 days of operation. These efforts are combined with more traditional approaches to recover sediment and water samples when less pressure sensitive parameters are being investigated.

Dr Ashley Rowden from NIWA, who is co-leading the voyage, says that it is “very exciting to for New Zealand to be part of this international research effort to generate novel insight on the function and importance of the great trenches of the deep sea. We definitely expect to find and describe new organisms and unravel their importance for the processing of organic material in the deep sea.”

Amphipod, Hirondellea dubia, an amphipod sampled at the Kermadec trench, 7000 m deep. [Hadal Ecosystem Studies (HADES) Kermadec Ridge 2014 expedition, led by the Woods Hole Oceanographic Institution and funded by the US National Science Foundation.]

The expedition has been years in the planning and is funded by the European Research Council (ERC)  and by NIWA. The voyage is the first in a series of expedition targeting three different trench systems in the Pacific, each experiencing different loads of organic material that sustain the processes and activity in the deep. The Kermadec Trench, which is situated in the proposed Kermadec Ocean Sanctuary, is the first of the trenches to be visited by the research team in this project.

More information:


Prof Ronnie Glud, Department of Biology, University of Southern Denmark
Ph +45 60 11 13 19


Principal Scientist - Marine Ecology