DARWIN/SYDNEY: A mottled yellow-green and brown saltwater crocodile lies mostly submerged in the muddy waters of an Australian river, only its ochre eyes visible above a triangular snout as it scans for prey.

When just such a reptile killed Charlene O'Sullivan's daughter 15 years ago, her first thought was that every one of the predators should be killed or caught around her home city of Darwin, to spare others from similar heartbreak.

Now she prefers a less drastic safety measure: education.

"I initially probably supported removing every crocodile," said O'Sullivan, whose daughter Briony was 11 when she was taken while swimming with friends at a waterhole in 2009.

"But you remove one crocodile from a creek or a waterway, another one's just going to move in," the former real estate agent said.

"We need to respect the environment we're in, know they are there, and think smart about what sort of situation you put yourself in."

O'Sullivan's change of heart is emblematic of a growing debate in Australia's tropical north, where unrestricted hunting nearly eradicated "salties" by about 1970, only to have strict conservation rules drive up their numbers ever since.

Now authorities are making tentative efforts - from more proactive messaging to physical removal of animals - to reduce the frequency of attacks, after 18 nationwide since the start of 2023, five of them fatal, database CrocAttack shows.

But they need to do that without threatening the survival of a species enmeshed with the economy and identity of the Top End, becoming a key part of the Northern Territory's A$1.5-billion ($980-million) tourism industry.

In the past two months, crocodiles have killed an Aboriginal girl in the Northern Territory and a doctor in the neighbouring state of Queensland.

But even a modest culling quota, unveiled in April, has rattled conservationists, Aboriginal elders and owners of tourism businesses.

The government wants to rid the territory of 1,200 reptiles each year from an estimated population of 100,000, to keep numbers where they were before a free-for-all by hunters drove them below 3,000 in the period from World War Two to the 1970s.

Queensland, estimated to be home to 30,000, raised the stakes this year by saying it would try to keep the animals away by shooting them with non-fatal rubber bullets.

It demurred from a recommendation by its chief scientist three years earlier to consider catching or killing larger animals.

Allowing crocodiles free rein would lead to deaths, said Hugh Possingham, the former Queensland chief scientist, whose 2021 study targeted animals longer than 2.4 m (8 ft).

"Wiping all the crocodiles out is ridiculous as well," he added. "You're between a rock and a hard place."

Conservation authorities in Western Australia, home to several thousand saltwater crocodiles, ruled out culling, said a spokesperson, adding there was no scientific evidence that it reduced the risk of attacks.

BITING BACK

But for the Northern Territory, the setting of Australia's top-grossing movie, "Crocodile Dundee", and with the world's highest ratio of saltwater crocodiles to people, awareness campaigns alone no longer suffice, the government says.

The 250,000 people who live there could soon be outnumbered by the animals, whose numbers have exploded by 3,000% in 50 years, it says.

That rankles those who work and live near crocodiles.

"The new Northern Territory plan is entirely unnecessary, wasteful and potentially dangerous," said Brandon Sideleau of Charles Darwin University, who started the CrocAttack database.

It could even bring increased attacks, if it led the public to believe that areas previously off-limits were safe, he added.

"If it hasn't got tiles on the bottom of it, don't swim in it," is the advice Tony Blums, owner of the Original Adelaide River Jumping Crocodile Cruises, gives to visitors, adding that better public education would save more lives than culls.

Tibby Quall, an Aboriginal elder of the Dungalaba, or saltwater crocodile, clan, also opposed culling.

"It's something you live with, something that's cemented to your culture, who you are and what you are," he said.

O'Sullivan, who with her partner now runs a crocodile farm that breeds thousands of the animals for meat and skins, says the venture has helped her to better understand and respect the predator that took her daughter's life.

"I don't for a moment blame the animal for what happened," she said. "It's an animal, Briony was in the waterway, the animal did what the animal does."