Police have arrested eight protesters that were on board oil company OMV's support ship in Timaru.
OMV's ship Skandi Atlantic has been occupied by more than 20 climate activists for more than 32 hours.
Police said eight people have been removed from the vessel and were arrested for trespassing.
It was unclear if there would be any charges at this stage, according to the police.
The protesters want to stop OMV from drilling three oil wells in the Great South Basin off the Otago coast and the Taranaki coast next month.
Extinction NZ said 10 activists remain on board the ship.
Greenpeace said those arrested are a mix of activists from different organisations, fighting for action against climate change.
Meanwhile, an Environment Canterbury councillor Lan Pham said the protesters' actions should encourage others to also do their bit in addressing climate change.
"We need everyone, everywhere doing everything they possibly can to respond to this [climate] emergency. That means people playing their role across society. Not everyone will be boarding ships to disrupt them but there are things that everyone can do in their own individual lives," Ms Pham said.