Into the abyss for deeper understanding

Hunched into a tiny submersible, scientists are voyaging to the ocean depths around New Zealand's giant undersea volcanoes to discover the weird and wonderful creatures that live there.

American and New Zealand researchers are on a 70-day "Ring of Fire" expedition mapping seafloor hotspots in the Kermadec Arc, north of White Island.

Some of the volcanoes discovered in an earlier exploration of the area are bigger than Mt Ruapehu.

"It's the first time we've been able to sweep through New Zealand's volcanoes like this. No one has been here before; it's like a flight into space," said New Zealand Institute of Geological and Nuclear Sciences chief executive Dr Alex Malahoff, the expedition leader.

On board the tiny submarine, launched from the US National Ocean and Atmospheric Administration ship Ka'imkai-o-Kanaloa, scientists plunge to depths of up to 1500m, where starfish, crabs and 30cm-long mussels live around volcanic seafloor producing hot, mineral-rich water and gases.

But key targets of this research project are the huge "mats" of bacteria that lie on the ocean floor "like snowfall".

"That's what we're after, the microbiology that is the base of all life," Dr Malahoff said.

Each volcano has its own special population of creatures feeding around it.

"It's just a fascinating world opening up. When we get back it will be lots and lots of lab work," he said.

The intensity and scope of the project have few parallels anywhere in the world.

Each dive in the submersible can last eight hours.

The submersible has manipulative arms and a vacuum system that sucks the marine creatures and microbes into steel canisters heated to the temperature of the water they are taken from.

The organisms are transferred to bigger tanks on board, and eventually taken to labs to be scientifically described.

Continuing research should show the risk of submarine volcanic eruptions and identify earthquake faults that could trigger tsunamis.

UNDERWATER HOT SPOTS

Large submarine hot springs within New Zealand's exclusive economic zone represent a relatively new branch of science with numerous implications and benefits.

Offshore New Zealand has some of the most active and unusual undersea hot vents in the world.

Scientists have mapped 77 submarine volcanoes in the 2500km stretch of seafloor between the Bay of Plenty and Tonga.

Many seafloor vents produce large volumes of hot mineral-rich water and greenhouse gases such as methane and carbon dioxide.

At some of these sites deposits of iron, manganese, copper, zinc, lead and even gold are forming continuously.

The "black smoker" plumes produced by seafloor vents supply trace metals that are vital to the lifeblood of the oceans.

Source: Geological and Nuclear Sciences Ltd