The Top End's mango industry is worth $122 million a year but the sector is under threat from climate change, industry figures have warned.

Key points: Mango growers fear projected temperature rises will affect fruit production

Mango growers fear projected temperature rises will affect fruit production Farmers are trialling heat-resistant fruit varieties

Farmers are trialling heat-resistant fruit varieties Fishing industries expect to face bigger swings in catch availability

One of the Northern Territory's largest mango farms is already confronting the effects of climate change.

"Rainfall is declining as a trend and prediction of temperature is becoming increasingly more difficult," said Martina Matzner, the general manager of Acacia Hills Farm.

With more than 30 years' experience managing mango farms in Darwin's rural area, Ms Matzner has been working on ways to adapt — including managing water more efficiently.

She is now part of a trial involving the NT Government that's growing more climate change-tolerant mangoes, which for now are being kept under wraps.

"They need to be both heat-resistant and able to withstand variability of temperature," Ms Matzner said.

The Northern Territory is the largest supplier of mangoes in Australia. ( ABC News: Matt Brann )

The Northern Territory's mango industry is its most valuable horticultural sector and produces two thirds of the total Australian mango crop.

Working to stay ahead of temperature variability

The NT Government said it was working with a range of mango producers who were concerned about the impact of climate change.

"We are expected to get higher rainfall, but much more variable, and much more extreme events, and warmer temperatures," said Mila Bristow, the NT Government's director of Plant Industries.

"If we get high temperatures, and we don't get a flowering event, obviously, no flowers, no fruit," she said.

Both Ms Matzner and the Territory Government said they were confident they would be able to innovate fast enough to keep up with some of the threats of climate changes expected until about 2090.

"I am confident we can stay ahead of temperature variability," Ms Matzner said.

"[But] questions like how to we deal with higher frequency of intense cyclones, that's quite a different kettle of fish.

"For example, we're working to understand different forms of planting the trees to make them more wind tolerant but we're at the beginning of that whole journey, so not quite there yet," Ms Matzner said.

Ms Matzner said she believed only more global efforts to stop carbon emissions rising would save her industry long term.

"We just need to accept that climate change is real, and it would be foolish not to be concerned about it, and once we can accept that, we can look at the solutions," she said.

Fishing industries also affected

Rik Buckworth has spent his career providing advice on how to manage risks, including climate change, to Top End fisheries.

He said he expected the Top End's $120 million Northern Prawn Fishery, and the $3 million mud crab and barramundi industries, would be able to keep responding to swings between good and poor seasons by varying their catches.

"The fact that the industry still exists tells us that they're really good at managing for that variability," he said.

Fisheries consultant Rik Buckworth said he was concerned fishing industries would eventually become overwhelmed by climate changes. ( ABC News: Jane Bardon )

He expected the biggest climate change hits to the industry would be caused by periods of successive dry wet seasons.

"Banana prawns, in particular, and barramundi, have a very strong relationship to the flow in rivers, and the extent of flooding across the floodplains.

"So, if you have runs of dry years, there is a risk there will be massive impacts on prawn fishery, and you will see very poor seasons for barramundi and mud crabs.

"The other obvious things will be when we have extreme events, like the massive mangrove die-off in the Gulf of Carpentaria, in response to very hot weather, or the extremes of cyclones, imposing a shock upon fish populations.

"So, we need to have management systems in place that are responsive to those."

Mr Buckworth said, although it may be difficult to predict, he expected the effects of more droughts and cyclones would eventually be too severe for the industry to manage.

"The problems will get worse, it depends on the global response that our society puts in place," he said.

"For example, if you look at the prawn fishery, there's 52 licences, 52 boats with crews, there's a whole industry that depends on them. So, I think the real worry here is the social impact."