The company’s ship G Expedition now only serves filtered water onboard, not bottled, while plastic straws are no longer used.

Brian Young, G Adventures’ managing director, said passengers can also participate in environmental projects while on expedition trips, such as helping to collect data on sea temperatures.

“We also have guest lecturers onboard as part of our education programme on the conservation of marine wildlife,” he added. “Our challenge is to do more to support the world’s oceans, protecting them from waste and plastics.”

Other marine policies include ensuring seafood on its menus is 90% sustainable, while guests and crew can take part in beach clean-ups in destinations such as Svalbard, Cuba, Sri Lanka and Thailand.

G Expedition recently ran its first zero-emissions trip in Norway, while the ship also picks up drifting plastic and nets to protect marine life.

The Ocean Health Fund, one of the initiatives run by the tour operator’s non-profit organisation Planeterra Foundation, supports 10 marine groups working on projects to protect the oceans.

Among those is Birdlife International’s Hookpad, which provides a new type of fishing technology designed to prevent birds being killed by traditional long lines.

Around 160,000 seabirds die every year after getting caught up in fishing lines – this particularly affects the albatross, with 15 of its 22 species currently in danger of extinction.