Posted on Wednesday July 7, 2021
A large gathering of Friends of Te Papa were enthralled by insights into life deep below the ocean surface from researchers Jess Hillman (Marine Geologist and Geophysicist, GNS Science), Sally Watson (Marine Geologist, NIWA) and Sarah Seabrook (Microbial Ecologist, University of Auckland/NIWA).
As 94% of Te Riu-a-Māui Zealandia is underwater, exploring the deep, dark ocean with a wide range of specialist technology and tools helps us better understand Aotearoa New Zealand’s complex geological history. Research over the past few decades has discovered vast undersea mountain ranges and thousands of new animal species, including diverse and unique animals that feed on chemicals flowing out of the seafloor.
Sally took us through the history of ocean exploration from initial mapping of known land masses to using echosounders on ships following WW1 to diving with deep-submergence vehicles. Mapping the seafloor from ships doesn’t catch the fine detail of topography or ecological hotspots. Now, autonomous underwater vehicles (AUVs) are capable of measuring details to the metre.
Sarah described the types of life found in the deep sea; an environment with a complete absence of light, temperatures of 1-4 degrees Celsius and very high pressure. Life including squids, octopuses, corals and barnacles thrive in the deep. New species are discovered every time this challenging environment is explored. Food is provided by the chemosynthesis process occurring around hydrothermal vents and methane seeps (oases in the deep).
We found out more about the gas beneath the seafloor from Jess as she described the phenomenon of ‘fiery ice’. Huge volumes of natural gas, most commonly methane, are locked up in gas hydrates, a solid form of water which is stable at high pressures and low temperatures. Found around the world on continental shelves and in permafrost, the Hikurangi Margin on New Zealand’s east coast is a prime spot for discovering more about fiery ice.
The researchers shared the disturbing experience of seeing plastic rubbish on the seafloor. Ways we can help reduce the human impact on ocean environments include purchasing thoughtfully, encouraging sustainable fisheries and restoring marine and coastal ecosystems.
Following the inspiring talk from Sally, Sarah and Jess, we had the opportunity to examine fascinating taonga of the deep and study a collection of maps. As 80% of the ocean floor is not yet mapped and only 2% is explored, discoveries made in future explorations of the deep unknown will help transform our understanding of life.