Two shark kill zones will stretch from Quinns Beach to Warnboro, and Geographe to Margaret River.

Two shark kill zones will stretch from Quinns Beach to Warnboro, and Geographe to Margaret River.

The shark-kill zones policy will be implemented by the Department of Fisheries in the metropolitan area after the contractor awarded the tender withdrew after receiving threats.

The commercial fisher that was awarded the contract for the South West region was informed on Monday, Fisheries Minister Ken Baston said.

Mr Baston would not release the name of the contractor at this stage.

It is not known if the South West contractor has also received threats.

The fisher and the department will be responsible for deploying, maintaining and patrolling baited drum lines, and providing a rapid response unit to deal with large sharks spotted within one kilometre off parts of the WA coast.

Under the plan any great white, tiger or bull shark more than three metres long will be shot dead.

Opposition spokesman on fisheries Dave Kelly said there were too many unanswered questions in regard to the policy and questioned why fisheries officers would be carrying out the work.

"It's just not good enough to send fisheries staff into the fray if the commercial fishers had so many concerns,"  he said.

The plan was waiting for approval by Federal Environment Minister Greg Hunt in order to by-pass the protected status of great white sharks.

Opposition to the plan has been fierce, with police investigating threats made to the fisher and to Mr Baston.

Greens MP Lynn MacLaren said Monday's announcement is further evidence the shark policy is a "shambles".

"After blaming everyone but themselves for not being able to find a commercial operator willing to operate drum lines off Perth, the Barnett government has announced that it will divert Fisheries Department's resources to do this dirty task," Ms MacLaren said.

"I guarantee that virtually no one at Fisheries will be happy about this; I would not be surprised if there are resignations.

"The WA Fisheries Department's mission is to conserve and manage the aquatic resources of WA to ensure there are 'fish for the future' – the shark cull completely contradicts this."

Ms McClaren called on Mr Baston to detail what other Fisheries Department duties will be put on hold while the shark policy is carried out.

"The man hours and expertise required, as well as the boat itself, is a hugely expensive and significant resource to expect Fisheries to provide at short notice," she said.

There have also been calls from protesters to boycott any company that submits a tender or carries out the work, as well as threats to interfere with drum lines.

One Facebook page which opposes the policy has even published the mobile phone numbers of the managers of two companies believed to have submitted tenders.

In recent weeks Premier Colin Barnett's office has been targeted by a protester, who smashed windows with a hammer.

There have also been peaceful protests, including the beachside protest in Cottesloe which attracted about 4000 people.