Scientists return from a six-week voyage with research on Antarctica's 'marine protected area'.
The NIWA vessel Tangaroa docked on Wednesday with valuable information on the Antarctic's ocean, atmosphere and ecosystems.
The ship was manned by 23 scientists, many of whom were from different fields and were there to study different things.
The main objective of the trip was to gather research in a 'marine protected area' - an area with restricted human activity for the preservation of animals.
Voyage leader David Bowden said such areas need to be maintained as it's a huge political feat to get them established.
"We were instrumental in establishing the MPA in the first place and we've been very proactive in formulating research and monitoring."
He said we need to maintain a robust monitoring schedule as the MPA is reviewed every five years and it has to be shown that work is being done.
Images sourced from NIWA
NIWA is concerned at the low sea ice levels that were seen on the trip.
David Bowden said he originally didn't think they'd make it to their destination because of ice but it was almost completely ice free.
"Whether [low ice levels] is a continuing trend or not, we will only find out in future years. But right now it's surprising."
He said only time and observation will tell what the cause is.
The vessel will return to Antarctica next year to collect seven instrument moorings which were left to record salinity, temperature and currents at different depths. Some of them also record the presence of whale or krill.
The voyage was a joint expedition between NIWA and the University of Auckland.