The tourism industry in the whole of New Zealand's South Island has suffered a serious downturn since the deadly Feb. 22 earthquake last year in Christchurch, the national industry group said on Tuesday.

The Tourism Industry Association (TIA) said a vibrant tourism industry was vital to rebuilding the economy of Christchurch and the surrounding Canterbury region and drawing back tourists.

TIA Chief Executive Martin Snedden said tourism contributed 2.3 billion NZ dollars ($1.82 billion) a year to the economy.

But since the February 22 earthquake, which killed at least 185 people, Christchurch had lost more than 1 million guest nights ( overnight stays in commercial accommodation), Snedden said in a statement.

Across the South Island, international guest nights had dropped by almost 1 million, he said.

The Christchurch Central City Blueprint for the city's rebuild was due for release next month, and the TIA had identified some key projects for the industry's recovery.

These included: a central city entertainment zone, offering both international and domestic visitors a temporary restaurant and entertainment zone; more accommodation, particularly in the hotel and backpacker sectors; and a definite location and schedule for rebuilding the Christchurch Convention Center.

"We are also calling for increased support for Christchurch Airport and its endeavors to secure increased international traffic, which helps not only Christchurch and Canterbury but the wider South Island," said Snedden.

"Christchurch Airport is the main gateway to the South Island and we want to do all we can to encourage airlines and passengers to come here."

According to Statistics New Zealand, the government statistics agency, the South Island had 1.1 million guest nights in April 2012, up 0.1 percent from April last year, but down 13 percent from April 2010.