Can shark culls reduce the number of attacks?

Following the commencement of the Western Australian shark cull, Chloe Warren, PhD student at the University of Newcastle, Australia, ponders the benefits of a more scientific approach to policy making.

Last weekend saw the gathering of over 4000 people on Perth’s Cottsloe Beach, brought together to protest the commencement of the Western Australian (WA) government’s shark culling policy.

The state government has authorised AU$6.85 million of funding for the project. Of this, AU$2 million has been allocated to the Department of Fisheries in order to track and destroy sharks, and another AU$2 million is to be spent specifically on tracking great whites and setting drum lines in order to kill them, should they come “too close” to the shore.

These measures have been instilled following an increase in the rate of shark attacks in recent times. For the past twenty years, roughly one person is killed per year; however, seven people have lost their lives to shark attack in the past three years alone.

Whether such increases in mortality can justify these measures is a matter of opinion…or is it?

Animal rights issues can and do instil a great deal of passion across a wide spectrum of social groups. The issue of shark culling has long been a topic of public debate across Australia. The masses seen on Cottsloe Beach on Saturday morning, as well as the 32,058 strong “anti-culling” petition are a testament to this.

While it’s expected that politicians and policy makers will consider their constituents’ opinions prior to passing any major bill, it’s also expected that they consider evidence where it is available.

Even if the public’s response to the cull had been overwhelmingly positive, some basic research of previous attempts to curtail shark attacks using similar methods should have been enough to stop this policy from being approved. In 1959 in Hawaii, a systematic cull lasting 17 years cost not only the lives of 4668 sharks, but also US$300,000 of government money: and yet there was no change in the rate of attacks. Even without such measures, shark numbers tend to decrease by one hundred million each year. So how can it be expected that a shark cull policy would have any impact on the number of shark attacks?

It appears that basic scientific principles (i.e. gathering and analysing data in order to solve a problem) have been side-stepped. While it cannot be denied that shark attacks are a tragic reality when they do occur, implementing poorly researched prevention plans is not only ineffective, but a waste of money and, tragically, life.