By RNZ

Scientists returning from a voyage into Antarctic waters say they found worrying evidence about how much ice has melted and how quickly.

The ice-breaking ship the RV (Research Vessel) Laura Bassi returned to New Zealand waters on Saturday morning after two months in Antarctica’s Ross Sea, which is part of the Southern Ocean.

The team of New Zealand scientists from the Antarctic Science Platform - along with a research team from the Italian Programma Nazionale di Ricerche in Antartide - crossed the Ross Sea on the ice-breaker to witness the sea ice retreat first-hand.

Changes to the sea-ice indicate that in the coming decades, coastal cities will need to be reconfigured because of sea level rise. Photo / Getty Images

Their research found that the ocean - the southernmost on the planet - is changing substantially, said NIWA and University of Auckland professor of physical oceanography Craig Stevens, who led the New Zealand team.

They found the area covered by ice had decreased dramatically, and in the past couple of years there had been record lows of the amount of ice surrounding Antarctica.

The expedition route Photo: Supplied/ Starboard Maritime Intelligence

The amount of salty and oxygenated water getting into the deeper parts of the oceans was changing.

The changes to the sea ice indicate that in the coming decades coastal cities will need to be reconfigured because of sea level rise, Stevens said.

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The effects these changes will affect mammals like penguins, whales and seals, and weather systems would also change around the Southern Ocean.

With a climate emergency underway, the work they were doing was urgent, he said.

“The scientific community [has] really got its pedal to the metal on this because it’s such a major challenge for humanity.

“This is going to affect ice shelves. It’s going to affect marine ecology. It’s going to affect sea level rise.”

Stevens said the research trip had allowed them to deploy robots, leave behind instrumentation to collect data and take measurements of all sorts of marine DNA and zooplankton.

But he said further research was needed to collect more data to inform their forecasting models better.

He hoped the information would be used to inform future government documents, such as for regional planning, and to inform the public about how the planet is changing.

- RNZ