DRUM lines, which use baited hooks to catch the predators, ensnared two tiger sharks — one 11 feet long, a Fisheries Queensland spokesman said.
“While sharks of this size are potentially very dangerous to humans, it is unclear if they were responsible for injuries caused to two swimmers this week,” he said.
“The shark carcasses will be towed well out to sea for disposal.”
The spokesman added that the drumlines would remain in place over the next week to reduce the risk to swimmers.
Shark attacks are very rare in the Whitsundays — a collection of spectacular tropical islands in the heart of the Barrier Reef, with the last encounter reported to be eight years ago, according to national broadcaster ABC.
This week’s incidents have revived debate about how best to reduce the risk of encounters between sharks and the growing number of people using the ocean for leisure.
Many conservationists and marine scientists object to killing sharks, and insist that drum lines are a blunt instrument because they often catch other creatures.
New South Wales, the country’s most populous state, has trialed non-lethal measures such as aerial drones to track sharks’ movements and “smart” drum lines that alert authorities to their presence.