Greta Thunberg marches in France against oil drilling
"The exit from fossil fuels must begin now by rejecting this project," said Natalie Herve, a spokeswoman for the group.
Thunberg was in the region after making an appearance Saturday at a demonstration against a local highway, where on Sunday police used tear gas to clear protesters who were blocking a railway.
The internationally known Swedish activist, wearing a pink raincoat and Palestinian keffiyeh, didn't speak at the anti-oil protest Sunday but danced and shouted slogans in French and English against the fossil fuel industry.
The wells would be drilled by Canada's Vermilion Energy, which has a concession near Arcachon until the start of 2035. The field has been in production since the 1960s and about 50 wells today produce a total of 1,500 barrels a day.
Opponents are hoping to block authorisation for the project, which has yet to be approved.
In 2017, the French government voted to stop domestic oil production by 2040.
At the beginning of December, the ecological transition minister Christophe Bechu said that as long as France needs oil, it is "not so bad that it comes from here instead of the other end of the world."