The American captain of a massive cruise ship faces trial in Marseille on Monday accused of using fuel with sulphur levels above European limits, as the Mediterranean port city grapples with the polluting effect of its drive to increase boat tourism.
The Azura, capable of carrying more than 3,000 passengers, is one of the largest in the fleet operated by P&O Cruises, whose parent company Carnival is also being charged.
Prosecutors in Marseille say it is the first time pollution charges have been lodged against a ship's captain on France's Mediterranean coast.
The city has wrestled with increased smog in recent years, as it seeks to attract more lucrative cruise tourism.
Authorities say shipping could be responsible for 10 to 20 percent of the damaging particulate matter in Marseille's air, which can cause respiratory problems and lung disease.
A spot check onboard the Azura in March found it was burning bunker fuel containing 1.68 percent sulphur, above the 1.5 percent limit.
High-sulphur fuel, which is cheaper than cleaner versions, produces sulphur oxides which contribute to acid rain and the acidification of oceans.
The ship's 58-year-old captain, whose name has not been disclosed, faces up to one year in prison and a 200,000 euro ($230,000) fine.
Tracked down by investigators a few days after the testing during a stop east of Marseille, he admitted using the fuel.
But he did not appear at a previous court hearing in July, when Carnival lawyers argued that the company was not responsible.
Sulphur in crosshairs
Environmental advocates say shipping is particularly harmful in Marseille, with fine particle levels 100 times higher near the city's bustling port than elsewhere in the city.
Even when docked at quai a single ship emits as much pollution as 10,000 to 30,000 cars, according to AirPaca, the regional air pollution monitoring agency.
The UN's International Maritime Organization has been lowering the allowed sulphur levels in ships for years, with a new limit of 0.5 percent coming into force in 2020.
But the NGO France Nature Environnement, which has welcomed the charges against the captain, says the new maximum is still too high.
It cites a 0.1 percent sulphur limit enforced in the Baltic Sea and other designated Sulphur Emission Control Areas, including the North Sea and along coastlines in North America and the Caribbean.
Marseille registered 1.55 million cruise ship visitors last year, and officials hope it will surpass the numbers in Venice this year to become the fourth-largest port of call for cruise ships in the Mediterranean.
The city is aiming for two million cruise line tourists in 2020.