Councillors voted unanimously at Monday's meeting to support David Owen's notice of motion against exploration in the Great Australian Bight.

Cr Owen said the council was the 16th Australian and the fourth Victorian council, joining Moyne and Corangamite shires, to lodge its opposition.

Norwegian company Equinor has an exploratory drilling permit for the Great Australian Bight, but has not commenced work.

Cr Owen said the council could not allow the bight to be put at risk by an accident such as the Deepwater Horizon oil spill that discharged five million barrels of oil into the Gulf of Mexico in 2010.

"The impacts would devastate marine life, fisheries and coastal communities and would seriously tarnish the pristine image of the Australian Southern Ocean and beaches," he said.

"The coastlines would be blackened totally and it could take decades to clean up the spill. Surfing, lifesaving, and all other water sports would be a distant memory on our coast and more importantly there would be an incredible impact on the Southern Right Whale nurseries and the endangered Australian Sea Lion, of which there are only approximately 15,000 left. Scientists estimate that 85 per cent of the species that live in the Great Australian Bight are found nowhere else on earth. They are truly unique and absolutely worth fighting for."

Warrnambool mayor Tony Herbert said all councillors had acknowledged the risks associated with mining oil and gas.

"The coastline of southern Australia could be at risk of an environmental disaster in the event of an oil spill or leak," he said.

"Our community has said time and time again that they highly value our coastline and it is our responsibility to protect what we have.

"There is also a need to express to higher levels of government our desire as a community to support renewable energy into the future."

Fight for the Bight Port Fairy organiser Ben Druitt commended the council's decision.

"With many other councils now considering this motion and rallies organised at all capital cities over the coming weeks, the time has come for Equinor to pull out of the Great Australian Bight. The people have spoken," he said.

"Our politicians may be climate change deniers, but they cannot deny that the political climate is changing. Fast. Sixteen local councils opposing Equinor's plans are a fine example of government representing the long-term interests of coastal communities.

"During March and April, capital cities around the country will host protests like Warrnambool. Over this time we ask that concerned community members write to their federal representative outlining their opposition.

"The open comment period for Equinor's environmental plan closed on March 20. Equinor are now required to modify their plans to address the 31,000 public submissions before their final submission to the regulator, NOPSEMA. Our hope is that they gracefully concede defeat and do not submit their plans to the NOPSEMA."

He said Cr Peter Hulin spoke of the "moral responsibility" councils had to represent the community's desire to protect the environment and respond in practical ways to climate change.

The council will write to Equinor and the National Offshore Petroleum Safety and Environmental Management Authority advising them of its position.

Council will also write to state and federal ministers, members of parliament and other Victorian councils along the coast urging them to do all they can to support a ban on oil and gas exploration in the Great Australian Bight given its importance for fisheries, tourism, internationally significant ecosystems and some of Australia's most threatened marine life.

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