Cruise lines will be forced to alter itineraries to counteract higher fuel costs and stricter environmental regulations by the middle of the decade.

The forecast came from Carnival UK chief executive David Dingle in an overview of the sector as part of the company’s 2011 annual cruise report.

New rules will require all cruise lines to make changes in the way they operate, he predicted. To meet its own environmental targets, Carnival UK claims to have reduced fuel consumption by more than 5% in each of the last two years and continues to do so.

But higher fuel costs from 2015 created by air emissions regulations will mean that the sector will have to modify itineraries to reduce cruise speeds, distances travelled and sometimes the number of ports visited, according to Dingle.

He revealed that the company’s ships have been cutting their speed for a number of years in order to preserve fuel. Dingle said the “ethical ambitions and the commercial realities” encourage Carnival UK to burn less fuel.

“One way of doing this, and something which we have, largely unnoticed, done for a number of years now is to reduce the speed of our ships,” he said.

“Adding in an extra day at sea here and there and thinking hard about whether a particular port is really worth visiting in relation to the extra fuel needed, are decisions which we regularly make.

“This has, for instance, encouraged us to feature more ports closer to home, most notably on our one-week cruises.”

This has led to an increasing popularity for cruises which focus mainly on France, Spain, Portugal and Norway.

“Indeed, despite all the wonderful destinations to which we take our guests all across the world, the greatest destinations of all are our ships,” said Dingle.

“As I have made clear on previous occasions, there is no doubt that all cruise operations are being impacted by a growing web of regulations.

“Although – on the environmental front – we are anxious to play our part as good citizens, there remains that ever-present danger of regulators maybe not exactly killing the golden goose but putting it on a very uncomfortable diet.

“We believe this message is getting through but we would like to see increased recognition for the significant benefits cruising brings to the UK economy.

“We would hope that this will come as we and the whole sector continues to grow and mature as it did in 2010 and will do again this year and in the future.”