Scientists delve into Kermadec Trench

Scientists have probed the depths of the Kermadec Trench — plunging more than 45 times the length of Auckland’s Sky Tower — to retrieve what’s believed to be the deepest ocean sediment sample collected by a special coring instrument.

The sample was obtained a week ago at 9994m deep using a wiredeployed corer, in a mission that took six hours.

The international mission returned to Wellington yesterday on board Niwa’s flagship research vessel Tangaroa.

The trench is 1500km long and comprises a series of deep basins that are more than 9000m beneath the sea surface. The deepest basin, Scholl Deep, is almost 10km deep and was discovered by a Danish expedition in 1952.

During this voyage, a combined Niwa and University of Southern Denmark expedition, scientists used a range of sophisticated autonomous deep-diving vehicles as well as traditional sampling approaches.

Professor Ronnie Glud, from the University of Southern Denmark, said the work confirmed recent research suggesting that the deepest trenches act as hotspots of intensified biological activity in the oceans.

He said that the findings showed that the deep trenches were far more diverse than originally believed.

Months of work now face the team analysing and interpreting the data and samples collected. Scientists will identify the microbial and faunal communities and seek to explain the variation in the organic carbon processing that was observed among the different trench basins.

The deep trenches host unknown and unique life forms that are adapted to extreme pressure.

Niwa marine ecologist Dr Ashley Rowden, who co-led the voyage, says the samples and data will help the team to understand how life at such conditions functions and differs from those at shallower depth.

The expedition included researchers from Denmark, Germany, Britain, Chile and New Zealand.