Queensland’s catch-and-kill shark control policy reveals more than the ethical dilemma of humans versus sharks
News analysis submitted in October 2019 for JRN8001 Analytical & Opinion Writing (Masters)
Queensland’s Shark Control Program (QSCP) is under scrutiny following the State losing its appeal to catch-and-kill sharks in the Great Barrier Reef Marine Park last month.
In a knee-jerk reaction, the State has since removed all 160 drumlines across 27 beaches within the GBRMP.
The Queensland Government claims it cannot meet revised conditions requiring animals found alive on drumlines to be released within 24 hours or fewer with insufficient staff trained to safely release sharks.
Yet, it has been more than two years since the legal fight began over its shark culling. In that same year, the Queensland Government, in a separate submission to a Senate Inquiry on shark mitigation and deterrent measures, said it had “fully trained marine animal release teams” for entangled whales.
Meanwhile, New South Wales and Western Australia have been tagging and releasing sharks using SMART drumlines. They trigger a GPS alarm when a magnetic contact is broken providing real-time alerts via satellite-linked acoustic receivers.
Queensland MPs have cited the Cardno Report commissioned last month to claim they face significant challenges to implementing the technology, including where to relocate sharks.
Now both State and Federal MPs are playing tit-for-tat accusing each other of risking lives.
But former Queensland Fisheries employee of 37 years, Geoff McPherson, who spent 16 years on the QSCP, is critical of the report.
“We had [SMART gear] working in 2005 but Queensland canned it as they were blackmailed not to mention acoustics as it was embarrassing for some academics who had absolutely no idea about acoustics,” Mr McPherson said.
Though Queensland’s shark control quandary is not just about technical difficulties nor the ethical dilemma of humans versus sharks.
Lurking underneath the surface, it reveals how our marine interactions may be altering shark behaviour and risking the collapse of marine ecosystems.
Queensland’s indiscriminate death haul
Rolling out in 1962, the QSCP currently has 234 drumlines and 27 nets spanning nine coastal regions from Cairns to the Gold Coast.
On the catch-and-kill list are at least eighteen species of shark though only three – the Tiger Shark, White Shark and Bull Shark – have ever been implicated in Australian fatalities.
There have been five fatal shark attacks in Queensland since 2001; in the same time frame, the QSCP has caught more than 14,500 marine animals, two-thirds of which were found dead, shot dead or euthanised including critically endangered species.
This is despite in 1991 the QSCP attaching acoustic alarms to nets to deter species like the Humpback Whale.
Organisations and scientists including Mr McPherson have criticised the claims of shark deterrents in addition to highlighting the side-effects of acoustic devices on marine animals.
“If you seriously think a AA battery can scare a whale or dolphin when a seismic airgun does not … then you really have to … pick out the rubbish from the science … then look at the mortality of acoustic tags on sharks,” Mr McPherson said.
“We have known about it for a decade, but the Senate redacted it.”
Are shark attacks on the rise?
Though in Australia, data of fatal unprovoked attacks in Australia reveals no discernible upward trend over the past two decades.
Data compiled from the International Shark Attack File reveals most unprovoked attacks since the 80s have been on ‘surface recreationists’ whose activities like surfing or skiing are on top of the water.
As marine biologist and shark advocate Bekki Hull explains, many White or Tiger Shark bites are a matter of misidentification.
“Sharks hunt from below so a surfer from the bottom looks exactly like a seal riding through a wave,” Ms Hull said.
And so too do our vibrations as we move about in the water.
Could we be training sharks?
Ms Hull shares a theory with other scientists that fish-finders and other manmade vibrations could be modifying shark behaviour.
“Big species of shark don’t usually come that close to shore … they hunt out in the deep ocean … for bigger species of animals … whether it’s for lack of food [from overfishing], or whether it’s all these boat engines putting electro-transmissions into the water, they’re attracted to it … that’s why there’s a lot of videos nowadays of sharks coming up and biting onto motors.”
Baited drumlines don’t attract more sharks, according to the NSW Government’s observational study. But what about mesh net bycatch?
Ms Hull explained sharks are attracted to the vibrations of struggling animals.
“That’s what attracts other bigger species of sharks, especially tiger sharks because they’re a bit lazy.
“If they can get an easy feed, they will.”
According to the Cardno Report, the fatal shark attack at Cid Harbour in Airlie Beach last year emphasised the risk outside of QSCP areas.
But there was no mention of boaties throwing fish scraps overboard in the area – anecdotal accounts confirmed in a separate report commissioned by the Queensland Government and published three days prior to the Cardno Report.
The big-picture consequences of culling
Ms Hull said without apex sharks at the top of the food chain balancing out populations below, a rippling effect known as ‘trophic cascading’ can occur.
The WA Government stated it has healthy shark numbers, but many concur apex shark populations have rapidly declined – largely from commercial fishing.
“It’s so hard to actually track how many there are of one species especially for a lot of the bigger species that are so migratory without tagging each individual,” Ms Hull said.
Though there are two things we do know: death by sharks accounted for only two percent of Australian coastal deaths according to Surf Life Saving Australia statistics and there is still so much to learn about these ancient creatures.