A senate committee inquiry into shark mitigation is being held in Perth on Thursday, just three days after a teenage girl became the 15th person killed by a shark in WA since 2000.

Surf Life Saving Western Australia general manager Chris Peck was the first to give evidence during the inquiry, saying there had been 40 direct shark sightings at Perth beaches in the past two years with 258 direct threat warnings issued and 4600 people cleared from the water during the same period.

"Our lifeguards have cleared thousands of people from the water... lives have been saved," he said. But Mr Peck said most of WA's shark attacks did not occur at the state's 16 patrolled beaches.

"Where surfers and divers tend to be are places we're not, it does put them at risk," he said. He told the senators he supported increasing beach, aerial and drone patrols as well as shark deterrents and did not believe drum lines had been scientifically proven to be effective.

He labelled a trial of a Clever Buoy shark detector system at City Beach in 2016 "premature" as the technology caused the beach to be cleared many times, but no shark presence in the area was ever validated.

"It's frustrating and irritating [to beach users] to be removed from the water," Mr Peck said.

"Beaches have closed for a number of hours... or days even."

An argument between two of the senators erupted after Committee Chair Peter Whish-Wilson implied the media gave an overrepresentation of coverage to shark deaths given Mr Peck told the inquiry an average of 14 people drowned at WA beaches each year.

Deputy Chair Lynda Reynolds said his comments were "disgraceful" and an attempt to diminish the lives of shark attack victims before Mr Whish-Wilson dismissed her concern and told her she could win an Academy Award for her "performance".

Sea Shepherd Australia managing director Jeff Hansen accused the media of creating a hysteria around shark attacks.

"I think there's a big problem with certain media outlets... The West Australian... the hysteria, the pressure is putting immense pressure on politicians and its leading to poor policies," he said.

"This debate needs to grow up."

Mr Hansen and chief shark advisor Natalie Banks argued solutions like drum lines and netting used in other states only created a "false sense of security" to ocean users, and did not actually protect people from an attack.

They referenced a shark fatality in Queensland where three bull sharks passed through eight drum lines and attacked a person, and 46 non-fatal encounters with sharks in New South Wales at netted beaches.

"How many sharks do we have to kill to feel safe?" Mr Hansen asked the senators.

Sea Shephard instead supported increases shark spotting, better availability of first aid at beaches, shark shields and shark alerts.

Family members of WA shark attack victims, Fisheries Minister Dave Kelly and personal shark deterrent companies are also due to give evidence at the inquiry which will conclude on Friday.