Each guest night is equivalent to one guest spending one night at an establishment.
Tourism Bay of Plenty head of marketing Kristin Dunne told the Bay of Plenty Times the numbers were affected by the lack of accommodation available compared with other parts of New Zealand.
"Our spend figures for the same period were up so it is a surprise that accommodation figures are down," she said.
"There are two issues with this monitor. The first is that the Bay of Plenty doesn't have as much commercial accommodation as other regions," she said.
"Only hotels, backpackers, motels and holiday parks are measured, which we have in our area - but we also have apartments, book-a-bach rentals and bed and breakfasts.
"The other thing is that 75 per cent of the visitors who come to the Bay actually stay with friends and family and don't stay in commercial accommodation."
Bay of Plenty Motels Association president Bruce Rutherford said he had not seen a drop in numbers of guests looking for accommodation in the Bay.
Instead he believed numbers were better than last year.
"I think numbers are slightly better, but I don't think it's hugely better.
"I think everybody's doing slightly better than they did last year in the Bay of Plenty," said Mr Rutherford.
He was not concerned about the statistics, saying events held in Tauranga had kept numbers up.
Mr Rutherford also agreed with Ms Dunne, saying there was a lack of accommodation in the Bay of Plenty area.
"There's never enough motel units available," said Mr Rutherford.
"A lot of people who come for the big occasions that are on, like the Aims Games that are coming up, there's just not enough rooms."
"There's enough to get us through winter and there's enough to get us through early summer, but during the summer period there's definitely not enough anymore," Mr Rutherford said.
Ms Dunne said the Bay had traditionally done well on tourism spending, particularly in the summer months.
"In terms of spend, we are the sixth-largest region. We bring $585 million into the region from tourism spend so we are bigger as a region for tourism spend than Northland, Hawke's Bay and Coromandel," she said.
By district, accommodation services in Tauranga clocked up 78,697 guest nights in total during the month of February, while in the Western Bay of Plenty there were 22,059 guest nights recorded, and 10,333 in Opotiki.
Foreign guest nights up 8.6pc
New Zealand-wide guest nights were up 5.4 per cent in February compared with the same month in 2014, marking the 11th consecutive month of rises.
Guest nights were up for all four accommodation types in February 2015, compared with February 2014. Hotel guest nights were up 4.9 per cent, motel guest nights were up 5.9 per cent, backpacker guest nights were up 1.1 per cent, while holiday park guest nights were up 8.4 per cent.
Tourism New Zealand chief executive Kevin Bowler said a growing market of international visitors and the worldwide popularity of the Hobbit films had contributed to a boost in New Zealand's accommodation sector.
"You can see in the data that the international guest nights are the fast growing area. They are up 8.6 per cent and what we are seeing is an increase in arrivals from a lot of different markets.
"Arrival growth right through summer has been strong and that has driven the commercial accommodation numbers up.
"The emergence of a stronger middle class in developing nations like China and India and then the halo effect of the Hobbit films have also had an impact."
