The threat of a United States-China trade war, and Brexit, had given the market the jitters, Tourism West Coast regional tourism manager Jim Little said.
The latest tourist spending figures, released recently, showed a 3% decline on the West Coast for the year to the end of June. June alone was down 23%, or $19million, compared with June last year.
International visitor arrivals were "softening" across the board, although forward bookings were about the same as this time last year. However, "we are getting more cancellations 30 days out", Mr Little said.
Europe, the United States and Southeast Asia were still good, but the UK was down as a result of Brexit, and there were fewer Chinese arrivals through Auckland and on the West Coast. Christchurch bucked the trend with more Chinese arrivals.
"Fox [Glacier] road closure has an impact, so we are pushing Lake Matheson a lot more. Waiho Bridge wash-out cost the Coast an estimated $50.4million in lost earnings, which has dragged our annual expenditure down significantly," he said.
Westland Mayor Bruce Smith said the cumulative effect of those two events alone was having an effect - "It's a lot."
Internationally, Brexit was going in circles, and the potential US-China trade war was making people wary.
"I've been around long enough, I've seen it three times. When you've seen it happen two or three times, `hello, here you go'. About every 10 years this happens," Mr Smith said.
"Greymouth is well positioned, and Buller too. But Westland - 60% of the tourism economy is in Westland. A significant downturn - I'm concerned it's on its way," he said.
Grey Mayor Tony Kokshoorn said he expected tourism would keep growing, "but there's definitely a lull".
He noted Air New Zealand had forecast a profit downgrade, which showed there were not enough "bums on seats".
The Chinese had led the growth and it was looking like there was now a "correction" in the market.
"But long-term is up."
BusinessDesk reported the drop in the number of overseas visitors from Asia in June was offset by an increase from the US and Australia.
About 213,536 short-term visitors arrived in New Zealand in June, up 0.6% on the previous year, Stats NZ said.
The number of Chinese visitors fell 3.1% to 18,334. There were 100,648 Australian visitors in June, up 1.9% on the previous year, while visitors from the United States rose 10.5% to 19,996.
"We had fewer visitors from Malaysia, Indonesia and Hong Kong, but more from Taiwan. Air New Zealand introduced a direct flight to Taiwan in November 2018," Stats NZ population indicators manager Tehseen Islam said.
Malaysian visitor numbers fell 44% in June compared with a year ago, while 20.1% fewer Indonesians visited New Zealand. There were 33% fewer visitors from Hong Kong. However, there were 61.3% more visitors from Taiwan.
The data showed annual visitors rose 2.7% to 3.9million people in the years to June 30. It was the slowest annual growth in a June year since 2013 and was well down from a peak of 11% in the year to June 2016, Stats NZ said.