For the first time in South Australia a drone has been used to plant samphire seeds at a hard-to-reach site on the coast at Port Gawler to revegetate the area.
Carrying a variety of seeds, the drone took flight to re-seed saltmarsh areas north of Adelaide to repair sections of the site damaged by off-road vehicles.
The drone spread 25 kilograms of seed across 6 hectares (roughly 3 AFL ovals) in around 6 hours, which would usually take days if planted by hand.
While this method of drone seeding is common in the agriculture industry, the use of drone technology has not yet been widely adopted for conservation use in South Australia.
Green Adelaide Team Leader Coast and Seas said that this is an exciting trial that could open up a lot of opportunities.
“When using drones in agriculture, it’s usually one type of seed at a time – so very uniform,” Mr Flaherty said.
“What we asked the drone company to do is use a mixture of seeds – some big, others light and fluffy.”
“If the trial proves successful, it will mean we can avoid the impacts of physically having to access sites like these and potentially it will give us a faster, easier and cheaper way to undertake works on offshore islands,” he said.
Saltmarsh and coastal dune areas can be difficult to access by foot or vehicle, so using a drone can reduce the risk of damage to areas being seeded.
While winter is the best time to plant these species, this site can usually only be reached during a small window in this season because of the tides and large rains.
Mr Flaherty explained that the site is very flat and any water (from the tide or rain) drains slowly, which also prevents accessing it on unsealed roads.
“By foot it’s really only possible to get within 200–300 metres of the site at this time of the year – any closer and you would start to sink into the ground.”
“The drone could get right to the areas we wanted to target and flew about one to two metres above the ground, spreading the seeds lightly on top of it.”
To make this possible, the drone company mapped the site beforehand and a flight path was created so that the drone could fly close enough to the ground but not crash.
Mr Flaherty said this is way of managing the site will help regenerate the area quicker.
“It’s expected the seeds germinate within about 4 to 6 weeks.”
“If the area was left to regenerate on its own, it would take significantly longer for the site to recover,” he said.
It will be around 18 months before the overall success of the trial will be known.