Pet warning: bull sharks on move in canals
A SUNSHINE Coast shark expert has warned canal-side residents to keep their animals away from the murky waters as bull sharks come out from hiding.
Tony Isaacson, a scuba diving instructor and shark conservation specialist, said as the weather heated up and the mullet and stingray population waned, bull sharks started to forage for food.
Sharks had already been spotted alongside residential homes at Twin Waters.
"Sharks are aware we are there, but they are not going to attack us because we are not their natural food source," Mr Isaacson said.
"However, if it is night time or there are conditions where there has just been rain or the waters are muddy, hunting instincts will be triggered.
"Sharks tend to bite first then think later."
Coast residents had come to understand that bull sharks, which can grow to 3.4m, were common in the canal systems.
Mr Isaacson said it was always a risk to go into the canals, but as the sharks went on the hunt for food, they were more mobile than ever.
"Sharks are there whether we see them or not," he said.
"They are not going to attack under ordinary circumstances, but if we put ourselves in harm's way or give off signals such as allowing pet dogs to swim in the canals that are murky like at Twin Waters, they could bite.
"The sharks in our canals could well have been there all year, or they could be ocean sharks who have followed the mullet into the estuary and into the lakes.
"We are in a drought cycle at the moment where the water becomes much clearer and we can see the sharks more clearly.
"Food is scarce and they will be more hungry and moving more than usual.
"Their main food source is mullet and stingray, but they are opportunistic feeders, especially when food is scarce."
Mr Isaacson warned those living canal-side to avoid going in the water at dawn or dusk or allow pets to swim in the water.
Bull sharks are aggressive, common, and usually live near high-population areas like tropical shorelines. They are not bothered by brackish and freshwater, and even venture far inland via rivers and tributaries.
Because of these characteristics, many experts consider bull sharks to be the world's most dangerous.