Shark attacks on humans are rare but the pure visceral reaction people have to an attack is normally detrimental to sharks. Government officials walk a delicate line between wildlife conservation and political survival. Calls for culling and shark nets are the norm. I agree that protecting beaches is important for both sharks and humans but there must be a balance.
Nets are one of the most brutal ways to control wildlife interactions with humans.
Shark nets are deployed near popular beaches and are roughly 150m long, 6m tall and are set in 10m of water. Sharks and other wildlife can swim over or around the nets, therefore the benefit to humans is minimal.
The effect on wildlife however is horrible. An estimated 15,000 animals have been killed, including endangered species like dolphins, seabirds, turtles and whales. Pictured below is a humpback whale that died a terrible death in a net. (1)
Whale Dead in Shark Net
Drum Lines (“dumb ones”)
The government of New South Wales ( NSW) has implemented a more high tech measure mixed with ancient fishing techniques to mitigate shark bites. This method takes the age old drum line and adds a real-time alert system to it.
The low-tech method is simple. Put an anchored buoy in the water with a chain, hook and some meat and you will probably hook a shark. As a result, unless you check the line and release the shark, it will die on that hook.
Smart Drum Lines
SMART ( Shark-Management-Alert-in-Real-Time) drum lines are a key feature by the NSW Government’s efforts to reduce shark bites and fatalities on the beaches.
The modern twist on “dumb” drum lines incorporates a triggering magnet that notifies a real-time satellite that there is something on the drum line.
DPI Scientists or contractors are notified via cell phone, email and text that there is an animal on the line and respond immediately . As result of the response, animals are released very quickly, therefore reducing the chances of death or trauma.
Animals are released further away from shore. Animals have a natural reaction to move further off-shore after release which provides a non-lethal method of protecting the beaches.
“The difference with the smart drum line is that the operator is made aware than an animal is caught on the line. From there it depends on the specific policy, availability of a boat and crew and sea conditions as to whether the animal gets released or not.” Alison Kock, marine biologist
Do Smart Drum Lines Work?
According to Fact Check there is data that shows a decrease in shark attacks.
“Fact Check’s assessment of historical shark attack figures and discussions with experts suggest that the use of traditional drum lines and shark nets do markedly reduce the incidence of shark attack when implemented on a regular and consistent basis, although this comes at a cost to marine life.”
Professor Colin Buxton of the University of Tasmania has told Fact Check “the use of shark nets and drum lines is a proven way of reducing shark attack, however the public need to understand and acknowledge that this works by killing sharks”.(4)
The article on ABC News states that Durban, South Africa experienced seven fatal attacks between 1943 and 1951 but here have been no attacks since 1952 when nets were implements.
There has only been one fatal attack on a protected beach in Queensland since 1962 when the measures were implemented compared to 27 fatal attacks between 1919 and 1961.
So even though there is some data to promote the use of drum lines and nets to protect beaches, we all have to remember to respect the ocean. It is home to a huge and wonderful spectrum of creatures that are part of our delicate eco-system.
Respect the Ocean and its inhabitants!