A shark cull by the Queensland government after two life-threatening attacks in the Whitsundays has led to a backlash.

Four tiger sharks have been baited and killed, after another was “humanely euthanised” on Sunday afternoon.

“This shark measures 3.7 metres and, like the others, would pose a serious threat to people swimming in the Cid Harbour waters,” Fisheries Queensland said in a statement.

But environmentalists say baited drum lines in Cid Harbour following attacks on a Tasmanian woman and Melbourne girl will not prevent more bites and can create a false sense of security.

“They may even make the situation worse,” Sea Shepherd Australia’s Jonathan Clark said in a statement on Sunday.

He said personal shark deterrent devices, aerial spotters, drone surveys, public education and alert systems played a bigger role in preventing attacks.

“Stop the nonsense about speaking of ‘effectiveness’ only in terms of their ability to kill sharks,” Mr Clark said.

“That bit is easy and it’s lazy policy. Making beaches actually safer is much harder and unrelated to their ability to kill sharks.”

Humane Society International marine campaigner Lawrence Chlebeck said public support for culling sharks had dropped and noted more sophisticated technology was now available.

“We acknowledge the need for the use of technology and reducing these sorts of incidences … but drumlines have been in the water since 1962. That’s 60 years ago now.

“The technology is there and we’ve moved on.”

Fisheries Queensland has dropped baited hooks into the waters where Justine Barwick, 46, and Hannah Papps, 12, were bitten less than 24 hours apart last week.

The government insists killing the sharks is for public safety and has the support from the Liberal National Party, saying the protection of people is more important than the protection of sharks.

“I think the action that is being taken at the moment is appropriate. We need to find this killer shark,” LNP deputy leader Tim Mander said on Sunday.

“It’s important that the public feel that they can swim in these waters safely and also that we protect the tourism industry up in north Queensland.”

National Geographic cameraman Andy Casagrande weighed into the furore on Twitter.

“When will basic intelligence & respect for the planet be a requirement for highly paid supposedly educated government officials?”

No Shark Cull advocacy group said culling sharks nearby was a “farce”.

https://twitter.com/ABC4EXPLORE/status/1043549658352627712

“The sharks responsible are probably swimming elsewhere, but three tiger sharks have paid for their lives. It is just like going into a park after a dog attack and killing any three dogs in response,” the group wrote on Facebook.

“No one actually benefits from this.

It just provides a false sense of security and makes it look like the government is doing something.”

Both victims in last week’s attacks remained in hospital on Sunday.

Ms Barwick was last known to be in intensive care after 18 hours of reconstructive surgery to her mauled right leg.

The family of Hannah Papps have expressed gratitude for the quick actions of those involved in her rescue.

“We would like to thank everyone who has helped and cared for Hannah, including the police, emergency services and the hospital teams,” the family said in a statement on Friday.

“We ask that everyone, including the media, please respect our family’s privacy during this very difficult time so we can focus our energies on Hannah’s recovery.”

-with AAP