The cyclone is also likely to have damaged the Great Barrier Reef, marine experts warned.
Six large rivers had reached major flood levels and were still rising in several areas, said the Bureau of Meteorology.
Meanwhile, Police Commissioner Ian Stewart said a man in Lamington National Park could be missing.
Queensland Fire and Emergency Services (QFES) shared photos of the shark on social media, warning members of the public to stay out of flood water near the Burdekin River.
When mixed with Queensland's cyclone and flood crisis, the man's drunk driving alongside other people's behaviour was deemed "foolish and stupid" by State Disaster Coodinator Stephan Gollschewski.
The search continues this morning for three people still missing after ex-cyclone Debbie ravaged northern New South Wales and southeast Queensland.
Don't create any artificial controversy over Dalai Lama's visit
The Dalai Lama had visited Arunachal Pradesh in 1983, 1996, 1997, 2003 (twice) and 2009, in addition to the ongoing tour. The Dalai Lama, who is on a visit to Assam and Arunachal Pradesh, will spend a week in Arunachal (April 4 to April 10).
"We can't afford to put other people at risk at this stage ... to try to find him". Look at the signs over there, the houses.
"People have lost everything".
Prime Minister Malcolm Turnbull urged people to heed the advice of authorities.
No deaths were reported so far from the storm, but there are still fears that fatalities may emerge after emergency workers logged more than 100 flood rescues during the night.
Some areas had about three times their monthly rainfall on March 30.
"The water's the highest I've ever seen it, heaps of shops are closed and most places shut at midday yesterday and everyone went home while they still could", Natasha Bolden told Reuters from the Murwillumbah Golf Club. "Do not cross flooded roads".
Sushma Swaraj calls on Malaysian PM Razak
He will also be accompanied by a large business delegation consisting of numerous top companies and businessmen of Malaysia. Speaking from the Rashtrapati Bhavan, PM Modi said the two countries have built a thriving economic partnership.
Cars sit submerged after heavy rain associated with Cyclone Debbie hit the Gold Coast suburb of Robina in Queensland.
Police say they recovered the bodies of two women from floodwaters late on Friday. Two women, aged 36 and 64, were swept away by floodwaters in northern NSW, while a 46-year-old man died in Murwillumbah from a heart attack when paramedics couldn't reach him.
Australian authorities Sunday said they found a third body in the aftermath of Cyclone Debbie and accompanying floods that swamped the country's east coast, as receding waters start revealing the human and economic cost of the storm.
In Queensland, strong winds of up to 120 kilometers per hour persisted Thursday as the worst of the low pressure system passed over the area.
The military has mobilised 1,300 soldiers to help assess the full extent of damage and aid the clean-up, with helicopters and planes deploying to restore infrastructure and supply emergency food, water and fuel.
Trump administration appeals block of travel ban
He added that the Trump administration was exploring all available options to vigorously defend the revised executive order . The second version of the travel ban, the president said, "is a watered down version of the first one".