Green algae protest in Quimper.

Video. WATCH: Green algae protest against farming in France

Greenpeace activists in France dumped nearly a ton of green algae outside the Finistère administrative headquarters in Quimper on Monday, in protest over the amount of green algae off the Brittany coast caused by industrial and factory farming.

Greenpeace activists in France dumped nearly a ton of green algae outside the Finistère administrative headquarters in Quimper on Monday, in protest over the amount of green algae off the Brittany coast caused by industrial and factory farming.

Fifteen members of the environmental group unfurled banners reading "Green algae: asphyxiated Brittany" and "Brittany polluted: the state is guilty".

Rotting green algae fuelled by these farms releasing nitrogen from fertiliser and animal waste can cause noxious gases and pose a danger to both the environment and to public health, according to activists.