Principal Research Engineer Andreas Marouchos says the ocean's nutrients are the "building block" of the marine ecosystem.
"We're collecting water samples all the way as deep as 6,000 metres, the average depth in this region is about 3 to 4,000 metres, last night we did the plunge down to 5,000 metres, and we're collecting water at different depths to measure the ocean nutrients," he told Sky News Australia.
"The ocean's nutrients are the building block of the ocean's ecosystem, not unlike your garden at home where you might have fertiliser to help other plants grow - well, this is the ocean's fertiliser."