The fight to control feral pigs in SA is continuing to prove challenging, with a heightened awareness of the animals felt in recent weeks.
SA Arid Lands Landscape Board general manager Jodie Gregg-Smith said the increase in feral pigs in SA had been noticed by different sources.
"This has come from a number of sources, with land managers advising us that they're seeing pigs," she said.
"Also recent control measures has seen us take out increased numbers of pigs in the last 12 months.
"Observations as recent as last week when we were baiting injection services we saw a number of pigs on properties."
The SA Arid Lands Landscape Board has recently leveraged some additional funding to heighten the control effort and landholder engagement in controlling the feral pigs.
Water from the Diamantina and channel country in Queensland is believed to be a key factor in the increase in the SA feral pig population.
"We're focusing on protecting both the conservation values, the Ramsar sites, the Cooper Creek in Queensland," she said.
"As well as working with PIRSA to monitor the disease that has been found in the pigs that we've killed through aerial control."
The diseases that can be spread via feral pigs and are particularly concerning are African swine fever, foot and mouth disease and Japanese encephalitis virus.
To help increase the capacity and awareness of landholders on how to manage feral pigs, a SA Disaster Rebuilding and Resilience Program has provided funding, with a co-investment from the Commonwealth government.
"To the greatest extent possible we will support aerial control or landscape scale management, but this needs to be in partnership with pastoral landholders," Ms Gregg-Smith said.
"We've recently deployed cameras along the dog fence where there have also been sightings.
"The interesting part of that is the pigs seem to be moving into the drier country."
There has been a significant rise in sightings of feral pigs particularly across the channel country of SA.
"Each time we've done an aerial control the numbers have gone up exponentially," Ms Gregg-Smith said.
"With so much water coming down the systems and a couple reasonable good years in the outback, we know that's just the perfect storm for pigs to continue populating.
"A real threat is the diseases they carry while remaining healthy themselves."
PIRSA Principal biosecurity officer Brad Page said that while AFS and FMD were threatening diseases, neither of them had been found in Australia.
"Australia is free of these highly contagious viral diseases and that's the most important point to get across at the moment," he said.
"Biosecurity is in place to try and to reduce the risk of these diseases making their way into Australia."
In addition to the risk of feral pigs bringing diseases into piggeries, the feral pigs can transmit diseases to humans.
There are self-sustaining farming feral pig populations in the North-East Pastoral district - where they have come from NSW - and also in the Riverland, with small populations in the Mid North.
"In the South East we get even more frequent incursions, with pigs walking across the Victorian border," he said.
"We believe there are feral pigs that have made it too far into South Australia, we think they've been illegally released by what can only be assumed to be selfish people."
The number of feral pigs in SA fluctuates, Dr Page said.
"At the moment things have been pretty good in the North East of SA, as it's been relatively wet up there for a few years," he said.
"There would be 1000s of pigs up there for example and I think the SA Arid Lands Landscape Board shot nearly 900 in a very brief operation very recently."
While KI used to be the dominant home for feral pigs, with approximately five thousand to 10,000 feral pigs there, the 2019-20 bushfires estimated to have killed approximately 90 per cent of the pigs and left the island with 875 pigs.
Given there was no dog fence around all of SA and Queensland and other states, Dr Page said there would never be a time feral pigs are eradicated from the state.
"We will always have incursions from other states, where we have no control of how many there are," he said.
"If I look beyond my lifetime there are technologies being researched right now, called gene drive and they offer the only hope that we will eradicate animals, like feral pigs.
"There's some tremendous work being done at Adelaide University on this gene drive and that presents a real opportunity to eradicate these established animals."
