The French Riviera city of Cannes announced it will implement a 0.1 percent sulphur cap on the fuel cruise ships use to dock in its port. If they exceed this limit, they will risk being banned from letting their passengers disembark. 

The initiative is being introduced by Cannes mayor David Lisnard, who said the aim is to reduce marine and air pollution while encouraging environmental protection. 

"It's not about being against cruise ships, it's about being against pollution," said Lisnard. 

"I said that we will no longer accept tour buses and cruise ship passengers on the ground coming from polluting cruise ships," he continued. 

Silversea Cruises CEO Robert Martinoli said it is in the interest of cruise ship operators to respect the regulations that help to reduce pollution. Martinoli said this helps preserve the destinations passengers visit on their cruises.

"Regulations have been improved and have been coming with the introduction of new techologies to make the engine more efficient and reduce the emissions.

"At the end of the summer, we will go into our maintenance cycle, so the ship will be out of service for two or three weeks, and we will implement the changes to the engines to make them comply with the latest environmental regulation," Martinoli said. 

Some cruise ships, such as Silversea Cruises' Silver Shadow were built 20 years ago and so this regulation ensures they comply with the latest standards.

In 2015, a national French law was introduced which fixed the maximum sulphur concentration level in maritime fuels to 3.5 percent. Under this law, ships are required to use marine diesel if they plan to dock at a port for more than two hours.