After five years of work, led by New Zealand and the United States, the world's second-largest marine protected area (MPA) has officially come into action in waters off Antarctica.
The Ross Sea MPA safeguards more than 1.55 million square kilometres of water off the icy continent, with more than 1.15 million square kilometres becoming a no-fishing zone.
Whales, seals and penguins are among the creatures which call the pristine landscape home, while the chilly waters also house nurseries of the Antarctic toothfish - which is often illegally fished and sold overseas as the Chilean sea bass.
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The creation of the massive protected area was a hard-fought battle, a joint proposal by New Zealand and the United States but which needed approval of dozens of other nations.
For Kiwi campaign The Last Ocean, the arrival of the MPA marks the end of an era. It's been working towards an Antarctica MPA since 2004 and on Friday, it will come to an end.
But while it's the end of the charitable trust, the creation of the MPA is a dream come true for co-founder Peter Young.
"The Ross Sea itself is a jewel in the crown of Antarctic waters and it's really fitting that it's the first large body of water to be protected around Antarctica," he told Newshub.
"We've brought our trust to a close. We feel like our job is done, and we do that with great satisfaction."
Fellow campaigner Rodney Russ, founder of Heritage Expeditions, told Newshub it's an emotional time.
"The number of public that came behind the marine mammal sanctuary is just part of what we've done here," he said.
"It was a long battle. It's an amazing place - it gets into your skin, it gets under your skin, it gets in you... It needs to be protected."
The MPA was approved last year at the annual Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) meeting. After five years of negotiations and debate, it was approved unanimously by the Commission's members - 24 nations and the EU.
NIWA's Dr Stuart Hanchet described it as an extraordinarily significant event.
"To get the agreement of 25 of the most powerful nations on the planet to agree on a Marine Protected Area of this size is nothing short of breathtaking and gives us hope for the future," he said.
The MPA will be in force for 35 years and Antarctica New Zealand chief executive Peter Beggs said it's important they now back it up with good science.
"If you're a scientist or just a Kiwi, I think it's very important," he said.
"The science that we're going to do in the marine protected area is going to define what that marine ecosystem looks like. And the science that we've conducted so far in the last decades in and around Antarctica has proven there's a strong link between what happens in Antarctica, [and] the weather that happens in New Zealand."
When it comes to the future, Mr Russ is hopeful that the MPA will help protect and conserve Antarctica's legacy.
"It's the public that will be the reason we protect it," he said.
There's still work to go. After all of the debates, there had to be compromises to get the MPA over the line, Mr Young said.
"Unfortunately one of the areas that has the most biodiversity and wildlife isn't in the MPA, but there's still a huge part of the Ross Sea that is," he said.
"The key fishing areas have been excluded from the MPA."
Now work is underway to protect more of Antarctica's waters. A proposed MPA off the East Antarctic ice sheet was the subject of discussion at this year's CCAMLR meeting, but was ultimately torpedoed by China and Russia.
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"The Ross Sea MPA is really a step in the right direction and it's just part of an ongoing process," Mr Young said.
Ultimately it's hoped that a series of interlinked MPAs will be able to safeguard all of Antarctica's waters, conserving the last continent for the future.