The stonefish, which is known to camouflage itself in the sand near coral or other rocks, is extremely dangerous — especially to unsuspecting beachgoers who may accidentally step on the fish.
"The stonefish has 13 sharp strong dorsal fin spines that are contained within a sheath of thick skin. At the base of each spine there are two venom glands that discharge their contents along ducts in the spine. When disturbed, the fish erects its spines, but maintains its position on the sea floor," the Queensland Museum explains on its website, noting most stings occur on the bottom of swimmers' feet.
The Australian woman quickly took to a local Facebook community page to warn swimmers at La Balsa Park, where the stonefish was spotted Sunday.
"I know it's a sea creature and that's where it lives, I wanted to let people know that it was found there," the woman wrote on Facebook, according to the Daily Mail. "There are so many people and dogs that swim in this spot. It was released back into the water but away from where someone could stand on it."
It's not uncommon for stonefish to be found in shallow waters in the northern portion of the continent. They've especially been wreaking havoc in the area this year — with at least four people reporting stonefish stings within an 8-day span in January, the Mail reports.
Crabber Brian Kesby reported finding at least two stonefish while attempting to catch sea critters in Maroochy Waters just last week.
"I just pulled the crab pots and it was just sitting on top," Kesby told the Sunshine Coast Daily. "Then the other one I found was inside it. There were a lot of kids swimming around there ... people need to be careful."
After reading the latest reports, several locals took to social media to urge friends and family members in the area to remain cautious and to keep an eye out for the coral-looking creatures.
"Eeewww that and worse stingers....great!" one Facebook user exclaimed.
"Remember this legitimate fear," another chimed in.
One man shared a photo he snapped of a stonefish caught near Bulcock Beach.
The fish's sting packs a painful punch, which can lead to serious injuries or even death.
"Multiple spines can often penetrate affected limbs, resulting in more extensive envenomation. The pain is immediate, excruciating and may last for many days. Muscular paralysis, breathing difficulties, shock, and sometimes heart failure and death can ensue," the Queensland Museum warns.
So, if you're planning on taking a dip in or around these popular swimming locations, particularly by reef flats, you'll want to wear proper footwear.
"An antivenene for stonefish stings has been developed. In the event of a sting, the victim should leave the water, apply first aid and seek medical attention as soon as possible," the museum suggests.