Tony Isaacson is warning about continuing aquatic events in Lake Kawana when overcast conditions and murky waters are present, for fear of attracting sharks close to competitors
Tony Isaacson is warning about continuing aquatic events in Lake Kawana when overcast conditions and murky waters are present, for fear of attracting sharks close to competitors Iain Curry

Education not drum lines key to shark safety

THE Sunshine Coast risked its almost untarnished reputation as a shark attack-free zone if organisers of Lake Kawana aquatic events involving swimming failed to respond to conditions known to trigger aggression.

Experienced diver and shark researcher Tony Isaacson says the impact of a competitor suffering an injury or worse as a result of a shark bite would cost the tourism industry millions of dollars.

And he has warned the loss to drum lines of a 4.7m tiger shark believed to have made Old Woman Island its home for the past 30 to 40 years has altered the food chain and would result in a more unpredictable creature replacing her.

Mr Isaacson pointed to the impact of a series of attacks around the northern NSW town of Ballina which had destroyed its tourism economy for two consecutive summers.

But he argues Queensland's shark control program, which mandates the slaughter of all sharks caught over three metres and which Premier Annastacia Palaszczuk is urging NSW to adopt, is not the answer.

He said with bull sharks, wet weather was the biggest problem.

"My biggest concern is that organisers won't pull the plug on events when conditions are overcast and the water murky,'' he said.

"Those factors trigger a physiological response from bull sharks to bump potential prey.

"Surfers would freak out at the number of bull sharks in their company that they never see."

Mr Isaacson said water events at Lake Kawana were particularly vulnerable.

"I have alerted all three tiers of government and have only had Mal Brough (former Member for Fisher) respond. His office overlooked the lake.

"My income comes from Airbnb and all my guests are involved in water activities. The Sunshine Coast has a perfect reputation (of being a risk-free area).

"We would be idiots not to take notice. Millions of dollars would be lost if our reputation was shot.

"We don't want to confront the Ballina situation."

Mr Isaacson said education to recognise high-risk periods, and the use of shark deterrent devices when the choice is to ignore them, were far more effective strategies than culling large sharks from their environment.

"Leg-rope shark-deterrent devices were mandated at the J-Bay Pro where the Mick Fanning incident occurred last year,'' he said.

Mr Isaacson uses them for himself and his guests when he takes them snorkelling on Old Woman Island but prefers not to use them when alone.

He said everyone who had ever stayed with him had rated snorkelling at the island the highlight of their Australian trip and it did not matter what other experiences they had tried.

The loss of the Old Woman Island apex predator in 2013 has seen an increase in green turtles to numbers that can't be sustained by the marine vegetation they feed on.

"She had her territory, was custodian of the break, surfers respected her and there were no incidents,'' Mr Isaacson said. "She was protector of her patch."

He said her experience and knowledge would be replaced by a "wild" shark resulting in unpredictable outcomes.

Rather than the Queensland shark control program contracts stipulating a bullet in the head for all animals over three metres, he wants sharks treated as a precious resource and an integral part of a sustainable biodiverse environment.

"We protect what's above the high tide line,'' Mr Isaacson said. "It's time to protect what's below it."