The Australia Institute has polled 1464 people about the proposal by Norwegian company Equinor to begin exploratory drilling for oil and gas in the bight late next year.

The poll by the independent think tank shows 65 per cent of respondents believe this sort of activity will have a negative effect on the natural environment.

But it also shows most people believe jobs will flow, with 57 per cent saying a new oil project would be positive for employment opportunities.

That's despite modelling by the institute suggesting about 27,000 tourism, fisheries, and aquaculture jobs could be wiped out in South Australia, Victoria and Tasmania if there was a catastrophic spill.

"This report shows that the economic and environmental cost of a major oil spill in the Great Australian Bight would be enormous," says the institute's South Australian projects manager Noah Schultz-Byard.

"Equinor has already had 239 oil spills in their history and, according to their own modelling, a major incident in the Bight would cover thousands of kilometres of the Australian coastline.

"While many are hopeful that the project would bring jobs, drilling in the Bight would actually create a relatively small number of employment opportunities, significantly fewer than the tens of thousands of already existing jobs that it would put at risk."

Equinor holds two exploration permits in the Great Australian Bight, about 500km west of Port Lincoln on South Australia's Eyre Peninsula, where tuna farmers, cray fishers, and oyster producers have staged protests about the potential threat to their livelihoods.

The institute also warns South Australia could face decades of subsidies and that revenue would be minimal.

"While oil and gas royalties can be important for state government budgets, decades of subsidy may be necessary before they can be enjoyed," it warns.

"Given the modest contribution of mining and gas royalties to the current South Australian budget, caution should be placed on such subsidies."

Australian Associated Press