The CSIRO vessel Investigator was due to leave Fremantle Friday January 8 for a 58-day voyage to the subantarctic Heard and McDonald Islands, about 4000km south-west of here.

The crew is investigating the link between active volcanoes on the sea floor and mobilised iron that swirls about, supporting southern ocean life.

Chief scientist Mike Coffin from the Institute for Marine and Antarctic Studies says they believe the iron is “critical to the growth of phytoplankton blooms, the foundation of life in the southern ocean ecosystem”. Phytoplankton also contributes at least half the oxygen in our atmosphere, and affects other elements that influence climate.

This is Professor Coffin’s sixth voyage to the region since 1985 and this time around the team will map the seafloor of the Kerguelen Plateau hot spot to search for active volcanoes and the source of iron-enriched waters.

Co-chief scientist Andrew Bowie says the Southern Ocean is “anaemic,” meaning it has little iron to support the blooms. If the team can show a link between volcanic activity stirring up iron for phytoplankton blooms, “it will be the first proven link globally between solid earth processes associated with hotspot volcanism and biological processes in the ocean”.

Oozing with scientific instruments, the $120 million, 94m Investigator can 3D map the sea floor, tow a deep sea camera, deploy sensors, and collect rock, sediment and sea water to track the hot mineral-rich water and find phytoplankton blooms.

With 26 scientists and students aboard, the 58-day journey is due to return to Hobart March 5.

by STEPHEN POLLOCK