WA is the deadliest place in the world for shark attacks, after the fourth death in seven months.
WA Fisheries senior shark research scientist Rory McAuley said the death of 33-year-old diver Peter Kurmann, of Vasse, off the South West coast yesterday, was just the latest in an "unprecedented" number of fatal shark attacks off WA in the past two years.
"I'm not aware of any series of fatal shark attacks, this number, in such a short period of time anywhere in the world," Mr McAuley said.
"So we really can't tell what's behind that.
"Last year a large proportion of the global shark fatalities occurred in WA.
"In other years we haven't even registered on the shark attack files statistics.
"So last year was particularly bad. This year has already started very tragically."
Mr McAuley said while the reduction of commercial fishing and protection of some shark species, such as the great white, might be responsible for the increase in attacks, there were other factors.
Just as likely, a rapid rise in WA's population - with more people swimming and engaging in other water sports - was to blame.
"Just by the law of averages if there are more sharks in the water it's likely that there's going to be an increase in the number of encounters between humans and sharks," Mr McAuley said.
"But equally if there are more people in the water there's likely to be an increased number of encounters between those people and the sharks.
"What we've seen at a decadal level is that the number of shark attacks is very strongly correlated with the human population of WA.
"So it's very hard to tease apart what might be due to the increase in shark numbers and distinguish that from the increase in human population." Premier Colin Barnett said he did not support a cull but there "may be scope" to allow increased fishing of sharks - even though the great white is a protected species.
"I am not advocating culling at all but I think there may be some scope, depending on the results of the research project, to allow increased fishing of shark, which used to happen and has been restricted for various reasons," he said.
"If the population of sharks is multiplying and growing, then I don't think those restrictions should be so restrictive."
Mr Barnett said it was unlikely a kill order would be issued against the shark suspected of mauling Mr Kurmann, if it had left the area.