The sign was made from seaweed washed up on the beach at Mettams Pool.

An anti-shark cull message left by protesters on a Perth beach. Photo: Shayne Thomson

Environment Minister Greg Hunt has waved through the West Australian government's controversial plan to catch and kill sharks to protect swimmers, exempting it from national environment laws.

In a letter to West Australian Premier Colin Barnett, Mr Hunt says he had deemed the plan should be exempt from the law because it is in the "national interest" of protecting public safety and tourism.

The plan was announced by the West Australian government following a series of shark attacks in recent years, most recently the death of a surfer in November who was mauled by a great white shark at Gracetown Beach, 270 kilometres south of Perth.

WA Premier Colin Barnett posing with a hook to be used to catch sharks off drum lines.

WA Premier Colin Barnett posing with a hook to be used to catch sharks off drum lines. Photo: Aleisha Orr

But it has raised significant anger among conservationists and parts of the community who object to the killing of the native animals in their habitat. Earlier this year 4000 people rallied on Perth's Cottesloe Beach against the plan.

The West Australian government is planning to deploy 72 baited drum lines each with a hook off Perth beaches and along the south-west coast.

Any great white, tiger or bull shark caught that is longer than three metres would then be shot and discarded in open water. Any shark less than three metres or from another species would be let go, but not if it is not considered to be in a condition to survive.

Greg Hunt

Federal Environment Minister Greg Hunt has granted an exemption for the shark cull. Photo: Alex Ellinghausen

Great white sharks are listed as "vulnerable" under Australia's environment laws and are also protected under the international Convention for Migratory Species.

In his letter to the West Australian Premier, Mr Hunt said a desirable part of "Australian culture" is that people understand the risk of swimming and boating in open seas, and that the government could not take away that risk at the general level.

"Individuals must take responsibility for their own water safety both as a matter of culture and practice. If we diminish that sense of self responsibility then we may create greater risk of misadventure, accident or tragedy," Mr Hunt writes.

But he said in this case it was clear that the public safety and and economic interests of the issue fell with in the "national interest" provisions to exempt an activity from the national environment laws.

"One does not have to agree with a policy to accept that a national interest exemption is warranted to protect against imminent threat to life, economic damage and public safety more generally," Mr Hunt writes.

In his formal reasons for exemption – dated January 10, but only made public on Tuesday – Mr Hunt points to research from the WA fisheries department that suggested shark strikes were rising in West Australian waters from one a year in the mid–1990s to two or three annually in period 2010-2013.

He also said economic damage from increased public concern about attending the beach was a nationally significant issue.

"Australia is an island country with a strong beach culture where water-based activities are carried out along most of its coastlines," the statement of reasons says.

"A loss of confidence in water-based activities impacts on tourism and other leisure-based businesses impacting on the Australian economy, making this impact a matter of national significant."

Humane Society International senior program manager, Alexia Wellbelove, said the exemption was "a complete disgrace."

"The proposed policy and consideration by the Federal Environment Minister lacks any real scientific approach, and fails to sufficiently consider the wider marine implications of the program," she said.

Ms Wellbelove said the group was now exploring legal options to challenge the exemption decisions. She also said it was looking at how the government would have to address the protection for the great white shark under the migratory species convention.

Campaigner for the Australian Marine Conservation Society, Pam Allen, said there was no evidence drum line programs would reduce the instances of shark attacks.

"These are freak, random events that depend on so many factors. Just because you catch one shark at a drum line it doesn't mean another one won't come in," she said.

She also said the program had the potential to hurt other marine wildlife such as turtles and dolphins. She said better monitoring and notification of sharks, along with better public education, was a better option.

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