Former Australian Greens leader Bob Brown has stood down as chairman of the anti-whaling group Sea Shepherd.
The move was made official at the organisation's board meeting on Wednesday.
After more than a year at the helm, Mr Brown will be replaced by former NSW Greens MP Cate Faehrmann.
Sea Shepherd Australia director Jeff Hansen said it was an honour to have Mr Brown serve as chairman.
"We're definitely sad to see him go but we're also very happy that he can finally have a bit of time with his partner Paul," Mr Hansen told AAP in Melbourne.
"We know that he'll be in our hearts and our minds and we know he'll always have us in his heart and mind."
Mr Hansen said it was a natural progression for Mr Brown to join as chairman of Sea Shepherd, having backed the organisation as Greens leader.
This was despite lack of support from the government as Sea Shepherd crews were battling in their anti-whaling effort against the Japanese on the frontline in Antarctica, he said.
"We felt really alone down there and he was there as the leader of the Greens going into bat for us time and time again, being our voice and defending Sea Shepherd relentlessly," Mr Hansen said.
"He's always said as long as he draws breath, he'll be Green and I think as long as he draws breath, he will always be a Sea Shepherd."
Ms Faehrmann said she was "absolutely honoured" to be voted as chair of the organisation.
And despite the group's "big win" with the International Court of Justice ruling curtailing Japan's "scientific" whale hunting program, she's expecting to remain busy in her new role.
"The oceans will need Sea Shepherd for many years to come, unfortunately," she told AAP from Perth.
"The threats just continue."
As chair, Ms Faehrmann plans to focus on illegal fishing, particularly of sharks and krill, Western Australia's and Queensland's shark culling schemes and the preservation of the Patagonian toothfish.
