Tourism is the backbone of Fiji's economy but it's under threat; the Pacific island paradise and many of the vibrant coral reefs that hundreds of tourists, particularly Australians, come to see have been killed off in mass coral bleaching events.

Key points: A "coral gardening" pioneer is working to save Fiji's reefs from bleaching

A "coral gardening" pioneer is working to save Fiji's reefs from bleaching Tourists coming to see coral are a crucial part of the country's economy

Tourists coming to see coral are a crucial part of the country's economy Fiji now has more dead than living coral, a resort manager says

But could "coral gardening" restore these reefs, and in doing so, save the Fijian tourism industry?

The man known as "the coral gardener", US-born marine biologist Austin Bowden-Kerby, pioneered the unique reef restoration technique and believes it can be part of the solution.

The semi-retired marine biologist who now calls Fiji home, has been experimenting with it for almost 40 years.

"In the beginning, I would just go, that's a purple coral, oh that's beautiful, oh that's nice," Dr Bowden-Kerby told the ABC.

"It was like in a candy store. I would just grow whatever was beautiful and looked rare."

Much like gardening on land, coral gardening involves propagating healthy coral and raising it in nurseries before transplanting it to degraded reefs.

Dr Bowden-Kirby now only works with "super corals" that can withstand higher temperatures. ( ABC News: Catherine Graue )

Fiji's reefs in crisis

"There's a lot of dead coral, there's more dead coral than live coral," Alex Wilson, manager of Fiji's Plantation Resort said.

He returned to take up the job in his home country only recently.

"When I came here and saw the situation of the corals, I thought, oh my god," he said.

"After being in Papua New Guinea, being in Cook Islands and seeing the coral there and how beautiful it is, I was very disappointed with what I saw here in Fiji."

Fiji's tourism industry is its biggest employer and continues to grow.

New data released last week revealed the total number of tourists visiting Fiji in 2018 was up 3.6 per cent on the previous year, earning Fiji a record $1.2 billion.

But while the industry may be growing, there is increasing concern the coral it so heavily relies on, is not.

Tourists are a vital source of income for Fiji and coral is a big drawcard. ( ABC News: Catherine Graue )

Warming ocean temperatures in recent years have seen mass bleaching events, where stressed corals expel the algae living in their tissues that they depend on for their energy and colour, become more common.

There are warnings that these reefs simply won't exist in coming decades.

The Intergovernmental Panel on Climate Change last year predicted that 99 per cent of reefs would go by 2050 if global temperatures rise by 2 degrees Celsius.

Dr Bowden-Kerby said that while bleaching events have happened in Fiji in the past, it's the frequency with which they are happening that concerns him, on top of new, human-induced threats.

"They've been through worse stresses in terms of climate shifts, but people weren't here," he said.

"Now people are overfishing the reef, adding fertiliser from the cane fields, so things are unbalanced. It's really a dangerous situation."

Coral raised in nurseries is eventually transplanted into the ocean. ( Supplied: Corals for Conservation )

In a coral bleaching event that hit Fiji in 2000, Dr Bowden-Kerby lost around 90 per cent of corals in his nurseries.

"I was like shocked, all of the corals I had planted died and I felt like my children had died," he said.

But he noticed that some corals had survived.

"I had whole nurseries die, thousands of corals. I was heartbroken so I will never plant a coral again unless I'm sure it's strong in the hot water, I'm not going to mess with it," he said.

Dr Bowden-Kerby now only works with "super corals", that are able to survive back-to-back bleaching.

A researcher swims by damaged coral following a mass bleaching event. ( ARC Centre of Excellence for Coral Reef Studies: Gergely Torda )

Growing the future

Dr Bowden-Kerby has partnered up with some in Fiji's tourism sector to have local resorts employ the country's first ever coral gardeners, who work to restore local reefs but also provide local communities and tourists with basic knowledge on reef restoration.

Sarah Makutu, 22, and Mere Tinai, 23, are both recent marine scientist graduates.

"I look at it as being part of the traditions. Growing up we were always looking after our land, so this is also a way of looking after reefs, and taking care of our waters and resources," Ms Makutu said.

Dr Bowden-Kerby hopes his initiative will be expanded across Fiji and provide at least 100 graduates with employment in the tourism industry.

Dr Bowden-Kerby shares his coral expertise with Sarah Makutu and Mere Tinai. ( ABC: Catherine Graue )

He says it can be replicated elsewhere in the Pacific, and Australia's Great Barrier Reef.

Some experts argue coral gardening projects are expensive and not viable on a large scale, but Dr Bowden-Kerby disagrees.

"How many people are involved in tourism … it's a big business in Australia," he said.

"If every resort, if every island, if every dive boat had a restoration site, if they had a coral gardener on duty, that was certified and trained … can you imagine? Thousands of sites, all over the Great Barrier Reef."

He plans to set up a model coral restoration site in Fiji this year, that will run international training workshops targeting Australians.