Science should sink shark cull

LYNN MacLAREN is a Greens MLC for south metro region based in Fremantle. In this week’s THINKING ALLOWED Lynn argues it’s not too late for the Barnett government to embrace science and devise an alternative to its widely derided drum-line policy to cull sharks.

WHEN is science “so-called”, instead of just plain science? Presumably, when scientific advice disagrees with government policy.

The Greens constantly pressured the Barnett government to provide scientific evidence to justify the cull from the moment the policy was announced last December.

Hundreds of marine and shark scientists wrote open letters and submissions to say drum lines would not make people safer and would harm the environment. No independent marine or shark scientist put their name to a public document saying the opposite, and eventually CSIRO and EPA confirmed the science consensus.

The drum line policy not only lacked science, it also lacked simple logic.

The government’s repeated explanation was that drum lines were a response to seven fatal shark attacks in WA in three years—the most recent involving surfer Chris Boyd at Gracetown on 23 November 2013. All seven attacks were by great white sharks, this being the only species confirmed as responsible for fatal attacks in WA in many decades.

Not one of the 172 sharks captured last summer was a great white. This single fact should have been enough to admit, by the cull’s end, a different strategy was needed. Even before then, serious flaws in logic had emerged: of the past seven shark fatalities, five occurred outside the government’s intended drum lining season and three outside the locations to be drum-lined.

Mr Baston told a June parliamentary hearing that drum lines worked because “if the shark came in close, it would take the bait instead of taking a human”.  He confirmed the baited hooks would do nothing to protect people using the ocean outside the times and locations that drum lines were present.

Given serious shark attacks have occurred from Hopetoun to the Houtman Abrolhos islands off Geraldton, and at least half of the time outside the drum line season, drum lines were clearly not going to address the majority of circumstances in which serious attacks have occurred.

The Barnett government pretended the policy was a response to public demand. Yet very poll showed a vast majority of Western Australians opposed shark culling. As the Greens revealed, the government also left unpublished its own research from 2013 showing most Western Australians did not support shark culls and had not reduced their ocean use as a result of recent fatal shark attacks.

Tagging programs—that is, science—show that the great white population off WA roams between Bass Strait and South Africa. The sharks can travel more than 100km in 24 hours and behave in a particularly transitory way off WA, with no marked tendency to habituate specific areas. Logically, therefore, even if one or several white sharks were killed, there would have been no substantial increase in safety because another great white was equally likely to take its place.

So what is the solution? The government’s 2013 research showed that most Western Australians want to be responsible for managing their own level of risk when they go in the ocean. This also happens to be the best way to protect people from such a wide-roaming and random hazard.

Cost-effective tools options available now to the Barnett government include—where nervous swimmers and local communities want it—ecologically-sound shark-proof swimming enclosures such as the Eco Shark Barrier successfully tested by the City of Cockburn at Coogee beach last summer.

They also include subsidising and improving access to personal and surfboard shark-repellent devices that already exist commercially but can be cost-prohibitive for ocean-user groups most likely to encounter a great white: surfers, divers and kayakers.

And they include urgently progressing improvements in the accuracy and effectiveness of our shark surveillance, monitoring and public alerts systems, drawing in part on expertise available from Capetown’s SharkSpotters program.

It has been claimed those who oppose culling will be to blame for any future shark fatality: such comments could only have been made in ignorance of the nature of shark attack hazard in WA and the inadequacies of the drum line strategy as a response to it.

It is a shame that for the past nine months, the government spent $1.3 million on drum line operations, plus untold internal resources from the departments of premier and cabinet and fisheries, justifying a policy that was never going to be able to provide genuine protection.

We are nine months behind where we could be, but if the government chooses to embrace informed rationalism and “so-called science” now, it won’t be too late to provide WA ocean-users with real options to manage their own level of risk.

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