WA mining magnate and Kangaroo Island land owner Andrew "Twiggy" Forrest is opposing plans by Norwegian oil company Equinor to drill an exploration well in the Great Australian Bight.
Mr Forrest's Minderoo Foundation released a statement last week listing its concerns about oil exploration in the Bight.
More than 100 KI residents attended an action on the beach at Vivonne Bay last weekend. See: 'Bight Back' beach action at Kangaroo Island
Last year he acquired the De Mole estate on the northwest corner of Kangaroo Island from South Australia's Brown and Wilkinson families in a deal worth about $10 million.
He has long been passionate about the oceans and is currently studying a PhD in marine ecology.
He launched this Flourishing Oceans initiative with a $100m commitment in July 2018.
Drilling for oil in the Great Australian Bight presents an unacceptable risk to an irreplaceable ecosystem, according to Minderoo Foundation's Flourishing Oceans initiative.
Flourishing Oceans chief executive Brigitte Smith said the Great Australian Bight was a globally significant marine reserve set aside to protect important marine species, many of which are only found in these waters.
Due to the significance of this environment, proposed exploration drilling in the Bight should not go ahead, she said.
"The Great Australian Bight is a pristine marine park home to unique and sensitive marine ecosystems," Ms Smith said.
"For example, the Bight contains the majority of the endemic and threatened Australian sea lion population and is the primary calving ground for Southern Right whales."
The Great Australian Bight doesn't have a proven hydrocarbon system. It is also remote, expensive and thoroughly difficult territory for oil exploration.
Minderoo is not opposed to responsible economic resource extraction. The risk factors associated with drilling in the pristine and globally-significant Bight make exploration or operation there unacceptable.
"I don't believe drilling should occur in this sensitive marine park when there are better alternatives," Ms Smith continued.
"Risking such a precious environment is not worth the reward."