The Lower South Island saw the biggest workforce drop, down 53 per cent.
Sectors with a high reliance on international visitors experienced the biggest job losses, with the culture and heritage sector down 64 per cent and tourism services down 61 per cent compared with holiday parks being down by 26 per cent.
"Three-quarters of respondents said the Tasman bubble was important for their business survival," TIA Chief Executive Chris Roberts said.
"However, the biggest impediment to recovery, selected by almost two-third of respondents, is the availability of staff."
The survey is the fourth that TIA has conducted over the past 12 months to assess tourism industry sentiment through the pandemic.
Twenty-two per cent of respondents were not confident they will meet their staffing needs as international travellers return.
Businesses in Queenstown, Canterbury and Auckland, in particular, are finding it hard to fill vacancies, the survey found.
Forty-three per cent of businesses said they need to get back to at least three-quarters of their pre-Covid annual turnover to remain viable.
Sixty-five per cent of respondents consider that the most important thing the Government can do is to enable borders to be safely opened - 95 per cent said opening up to other countries was important or very important to their business.
"In terms of what the industry can do to help itself, respondents said they want clear leadership, and co-operation across industry and with Government to find solutions," Roberts said.
The results were released at the start of the Trenz Hui 2021 in Christchurch to set the scene for attendees' discussions on the future of the international tourism sector.