Former fisheries minister Troy Buswell - one of the key architects of the Barnett Government's new shark control policy - has admitted images of a shark being shot in the head at close range are "not pleasant".
But he is adamant the method is the most humane way to kill a shark and was unapologetic about the policy's effect.
"We announced a policy which pretty much said this: that we would set drum lines to catch sharks, to protect people. That drum line caught a shark," Mr Buswell said yesterday. "Our objective, and the very strong direction to the (contracted) fisherman, is to - as humanely as possible - euthanise the shark.
"Now, I'm not sure of the condition of that shark when it was brought alongside the boat. He obviously formed a view that it needed to be shot to ensure it was deceased. I don't have a problem with that.
"We are trying to protect the public, and we are trying to deal with the sharks in the most humane way. I think that's what he did."
Mr Buswell said he had been "very surprised" by some of the negative public reaction to the shark policy, under which baited hooks will be set 1km offshore at five metropolitan and three South West beaches.
"I think there's been some incredibly emotive commentary by a whole range of people, some who have very little knowledge of what they're talking about," he said.
"What amazes me is that these people respond in this way to the WA Government's efforts to protect our public, and say nothing about what's been happening in Queensland or NSW for years and years and years. I mean, it's lunacy.
"The policy will be rolled out because we have a responsibility to protect - where we can - people who use beaches. It's in a limited part of the State. I think that time will show it to be effective.
"I suppose my question to those people who are so violently opposed to what's happening in WA is why do you value a WA shark so highly and why do you value protecting WA (human) life so lowly compared to the rest of Australia?"
Asked if he could see why some people found the image confronting, Mr Buswell said: "Of course. It's not pleasant. But . . . all the advice I have is that is the most humane thing to do."
Premier Colin Barnett told The Weekend West he felt the Government had no choice but to act after the November 23 death of surfer Chris Boyd in Gracetown.
Protests are due to be held on Saturday morning at Cottesloe, Warnbro, Bunbury's back beach and Dunsborough's Meelup beach, where the first shark caught by a drum line was found on Sunday.
Protests are also planned for three beaches in NSW, Burleigh Heads in Queensland, as well as in Melbourne, Torquay, Adelaide, Glenelg and Wellington.
Organisers have promised an even bigger turnout than the estimated 3000 people who attended a protest at Cottesloe beach on January 4.
The Government hopes drum lines can be set off Perth beaches this week. Department of Fisheries officers have been given the task after commercial fishermen pulled out of the Government's tender process.