The Department of Environment and Science (DES) received 1146 reports of saltwater crocodile sightings in 2021 — up from 616 in 2020.
"This is the highest number of reports since results were first collected in 2009," DES director northern wildlife operations Lindsay Delzoppo said.
He attributed the rise in part due to the "remarkable update" of the QWildlife app, which launched last November.
"The QWildlife app has been highly popular in 'croc country', with many people also submitting photos or videos with their reports when using the app on their smartphones or tablets," he said.
"The QWildlife app also allows people living in or visiting croc country to find out where there have been sightings and the locations where any 'problem crocodiles' have been declared within the previous 30 days."
But Mr Delzoppo warned that just because a location had not been marked down on the app, it was not necessarily safe.
"Crocodiles are highly mobile and may turn up in any waterway in croc country at any time, even if they haven't been seen there before," he said.
But he also said the increase in reports "does not necessarily" correlate with an increase in crocodile populations.
"This is because more than one person could report the same crocodile, and it is now much easier for the public to report sightings via the QWildlife app," Mr Delzoppo said.
"The growth in residential development in known crocodile habitat also means there are more people to make these reports."
Mr Delzoppo said thousands of Queenslanders and interstate visitors are expected to spend the Christmas holidays season near waterways in croc country.
"Remember, you are responsible for your own safety in croc country, which begins at the Boyne River south of Gladstone, and extends up the east coast and across far north Queensland," he said.
"I encourage people who are travelling to croc country over the Christmas holidays to download the QWildlife app in advance and familiarise yourself with it."
Members of the public can report crocodile sightings (and should do so as soon as possible) by entering the details to the QWildlife app or by calling 1300 130 372.
How to stay CrocWise
- Expect crocodiles in all central, north and far-north Queensland waterways even if there is no warning sign
- Obey all warning signs
- Be aware crocs also swim in the ocean and be extra cautious around water at night
- Stay well away from croc traps, including when fishing and boating
- The smaller the vessel, the greater the risk, so avoid using canoes and kayaks
- Stand back from the water's edge when fishing and don't wade in to retrieve a lure
- Camp at least 50 metres from the edge of the water
- Never leave food, fish scraps or bait near the water's edge, at campsites or at boat ramps
- Never provoke, harass or feed crocs
- Always supervise children near the water and keep pets on a lead