IT'S A WELL-KNOWN fact that bull sharks frequent the Brisbane and Bremer rivers, but what many Colleges Crossing regulars might not realise is just how close they are paddling to potential danger.
Ipswich angler Jason Reeve regularly catches juvenile sharks - around the 1.3m-long mark - below the lookout at Colleges Crossing.
The area below the lookout is often swimming with young families enjoying a cool-off among the picturesque surrounds of the park, but once the sun goes down it is one of Mr Reeve's favourite places to hook a good-sized shark.
As recently as Sunday night he caught another 1.3m bull shark, but that's not the only place he's caught them.
The local angler also tries his luck at Kookaburra Park and the Bremer River around North Booval, and often reels in a decent sized little predator.
"Most people I show the photos to get a shock," Mr Reeve said.
"That isn't the worrying part; we have 2m-plus females frequently coming up into the system to give birth.
"Basically our systems are a nursery. If there a small ones, there will be big mothers frequently passing through."
Ocean and Coast Research shark expert Dr Jonathan Werry said river systems like the Brisbane and Bremer were used by bull sharks for their young to mature.
About this time of year, large females will swim many kilometres upstream, where they "drop off" new-born pups and then swim back out into the ocean. Of the adults, only female sharks have ever been tracked so far upstream, and it is thought that they may only stay inland for a matter of hours before returning to salt water.
Dr Werry said there were a few reasons why bull shark attacks were so rare in the Ipswich area.
"The sharks need to grow to about 1.3-1.5m before they move beyond eating crabs and fish," he said.
"When attacks do occur, it tends to be over deep holes at dusk or dawn, because during the day they hide in the deeper holes. Younger sharks tend to avoid anything larger than them, because bigger bull sharks eat smaller ones."
Shark attacks are rare. The most recent reported case involved a teenager claiming to have been being bitten on the hand at Karalee in March 2005.
Regular Brisbane and Bremer River water skiers have told the QT that while shark sightings are common, they have never felt threatened.
Mr Reeve said he'd heard of sharks "headbutting" smaller swimmers.
"They are inquisitive creatures," he said.
Dr Werry said he did not recommend swimming anywhere that sharks were present, but that those who do should avoid swimming at dusk and dawn, and also avoid murky water, where a shark could mistake your hands or feet for a tasty mullet.