Vancouver's tourism sector is set to lose about $18 million next year after Carnival Cruise Lines said it'll start using Seattle as its main departure point for passengers taking Alaskan cruises.

Starting in 2010, 17 week-long Alaska cruises will operate from the Port of Seattle aboard the 2,124-passenger Carnival Spirit.

At present, the Spirit departs out of Vancouver and tourism officials say it's going to have a significant impact on the local economy.

"Generally we get about $2 million worth of economic activity for every sailing," Steve Pearce, vice-president of Tourism Vancouver, told CTV.ca on Tuesday.

"Carnival is going to be pulling nine sailings out of Vancouver so that's about an $18 million hit to our local economy."

Vance Gulliksen, a spokesperson for Carnival, said the decision was made to "offer a new Alaska cruise option" for customers.

"This new itinerary will provide our guests requiring air transportation with more convenient air options and significantly lower air costs," Gulliksen told CTV.ca in an email.

"It will also allow our guests in some areas of the western regions of the U.S and Canada to drive to Seattle, making our Alaska cruises even more affordable."

Pearce said he suspects the current "economic circumstances" were a main factor behind Carnival's decision.

"The bulk of passengers are American citizens and they feel that they can move their inventory a little closer to their market," he said.

Although there are about 270 sailings out of Vancouver annually, Pearce said the loss of the Carnival Spirit is "nothing to sneeze at."

He said his organization has been working hard with cruise operators to remind customers that their Alaska vacation starts in Vancouver.

"We know that one of the common complaints from cruise passengers once they've taken their trip out of Vancouver was that they weren't aware that this city has what it has here -- it's proximity to Victoria, Whistler, to the Okanagan," Pierce said.

"It's not uncommon to get people complaining that if they had known that this was what Vancouver was they would have stayed here longer."

He said if the decision were solely based on price, it'd probably be cheaper to fly out of Seattle.

Pierce said he hasn't seen any other cruise lines taking similar measures.

He also said he views the move as a "tactical decision" by Carnival not a "strategic decision."

"The Alaska cruise industry is going to continue to be very robust," Pierce said. "We'll continue to get our share of customers in a market that is going to grow."