Illuminating the depths

From the belly of the Tangaroa research vessel, a world is revealed.  

Blog by Lauren Timms, Assistant Collection Manager, Te Mana o Rangitāhua 

A science expedition to New Zealand’s most remote islands has exposed never before seen underwater forests and areas of the sea floor. The Rangitāhua region comprises several small islands along the Kermadec Ridge, the largest being Raoul Island. Its isolated position makes it a novelty and an enigma just waiting for discovery. 

Aboard the Kaharoa voyage during October-November, deep sea oceanographers and ecosystem specialists uncovered previously unknown environments using specialised equipment. These environments are too deep for SCUBA observation so this represents the first time they have been observed by humans.  

The Deep Towed Imaging System (DTIS) takes footage of the landscape and life at remote depths. While deployed around Raoul Island, the DTIS team uncovered vibrant reef systems up to 300 meters deep. Large Gorgonians, colourful fish and flourishing corals indicate an old and well established ecosystem. It was a very exciting find for Rob Stewart, Sarah Searson, and others onboard.  

Bathymetry is the measurement of the depth of the water. It produces seafloor maps that use colour to indicate depth. On the voyage Susi Woelz’s primary role was to compile information gathered by the ship mounted Echosounder to make colourful bathymetric maps. Before this voyage, large areas surrounding Raoul Island remained unknown and appeared black on the map. Following Kaharoa, the map is largely complete which means it is safe to explore the area with other equipment. 

Ngāti Kuri first explored Rangitāhua centuries ago and iwi members were part of Kaharoa to discover more of the region's mysteries. Rangitāhua remains one of the most pristine environments in the world, and one of the most unexplored. Together, Ngāti Kuri and scientists are part of a 5 year project to better understand these ecosystems and how to preserve them for the future. 


Images 1 & 3: Newly discovered deep-sea reefs off Rangitāhua
Image 2: Bathymetry Map of Raoul following the Kaharoa voyage  

Rangitāhua expedition

Explore the full series of blogs from the Rangitāhua voyage.