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Shelly Beach near Ballina, one of the new shark net locations, was the scene of a fatal shark attack in February 2015. Dave Hunt/AAP, CC BY-SA

The recent spate of shark attacks in New South Wales has led to the announcement by NSW Premier Mike Baird and Primary Industries Minister Niall Blair of an expansion of the Shark Meshing Bather Protection Program. New shark nets are being installed at five locations in the Ballina and Evans Head area of the state’s north coast.

However, shark nets are controversial because they are designed to kill potentially dangerous sharks. In the process, nets may also injure or kill non-target animals, including endangered and protected species.

Whether or not shark nets actually reduce the risk of an attack is also a tricky question, although there has only been one fatal attack at a netted beach since the NSW meshing program began in 1937.

While some people welcome more nets, there is increasing support for the use of non-lethal shark attack mitigation measures. This is largely driven by concerns about the potential ecological impacts of shark nets. However, there are also substantial economic and logistical constraints on deploying nets at all locations where people might enter the water.

Beyond shark nets

So what other strategies can we use? As well as large-scale initiatives to reduce the chance of shark attacks at popular beaches, such as the installation of shark-proof barriers and enhancing public awareness of attack risk, concern about shark attacks has also led to a proliferation of personal shark deterrent technologies – so much so that there are now too many to list and describe in detail.

Broadly, the devices include those that produce strong electrical or magnetic fields, those that produce a repulsive light, sound or odour, and those that reduce the visibility of the wearer to sharks.

Shark net trial locations, NSW north coast. NSW Department of Primary Industries. Can new devices prevent attacks?

Because of the upsurge in technologies being developed to reduce shark attacks, shark researchers are often asked which are the most effective deterrent devices and which do not work.

However, many of these technologies are still in development. Fewer still have undergone independent testing of their effectiveness in deterring sharks under different conditions. This means that the general public have limited information when deciding if a particular shark deterrent might be suitable and whether it is worth purchasing, especially given that most commercially available devices cost several hundred dollars.

Our current research focuses on the new generation of magnetic and electrical deterrents, especially those designed to be used or worn by surfers and swimmers. We will test these devices in the field with white sharks to assess their efficacy. In the case of the electrical devices, we will map the electrical fields they emit to assess the strength and shape of these fields.

Importantly, by combining these approaches, we can correlate electric field strength with actual deterrent efficiency. This will help to streamline the development and testing of such devices by weeding out prototypes that do not work because their electrical fields are too weak to repel a motivated shark.

Fundamental shark research is essential

Our research will also focus on the physiological response of the shark’s electroreceptive system to the devices’ electrical and magnetic fields. This information will provide an improved biological understanding of the effect of these different stimuli on the sharks’ senses.

History shows that developing shark deterrents based on what we know about shark sensory biology is far more efficient than a trial-and-error approach. This research will also assist in adapting some of the personal deterrent technologies or concepts for use at a larger scale, such as the electric shark barrier being trialled in South Africa.

Any shark attack can be traumatising to the people directly or indirectly involved, and it is critical to reduce risks as much as possible. However, it is also important that scientists and governmental agencies do not overstate their ability to reduce risks of a shark attack.

The general public should be aware that there is no magic bullet when it comes to preventing attacks. No deterrent will prevent every shark attack in every situation.

The only way to remove all risk of an attack is to swim within a well-maintained enclosure that excludes sharks by means of an impervious barrier, or to stay out of the water altogether.

For those determined to venture further into the ocean, we encourage responsible SharkSmart behaviour. This includes staying close to shore, swimming in groups and avoiding large schools of bait fish.

Nathan Hart has received research funding from the Australian Research Council Linkage Program, The State Government of Western Australia Applied Research Program, The NSW DPI Small Grant Program and the Sea World Research and Rescue Foundation to study shark sensory systems and shark deterrents. He has provided design criteria (under contract) to companies that market shark deterrent wetsuits (Shark Mitigation Systems) and advice (based on our independent testing) to companies that produce electronic shark deterrent devices (Shark Shield).

Charlie Huveneers receives funding from NSW DPI Small Grant Program.

Giraffes have been classified as vulnerable to extinction. Chester Zoo says humans are to blame.

The population of the world's tallest land mammal, the giraffe, is shrinking. Chester Zoo says humans are to blame.

The tail of a feathered dinosaur has been found perfectly preserved in amber from Myanmar.

Government says it will not support highly polluting method of releasing gas from coal seams

A highly polluting method of extracting gas has been effectively killed off in the UK after the government said it would not support the technology.

Underground coal gasification, which involves injecting oxygen and steam underground to release gas from coal seams, would massively increase UK carbon emissions if exploited, according to a government-commissioned report.

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Historians unveil a digitally-reconstructed image of the face of Scottish king Robert the Bruce nearly 700 years after his death.

The giraffe is at risk of extinction after a large decline in numbers over the past 30 years, according to the International Union for the Conservation of Nature, which released its latest ‘red list’ of threatened species on Thursday. The eastern gorilla and whale shark are also deemed at high risk

• Giraffe facing extinction after devastating decline, experts warn
  

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Germany and Spain among those accused of failing to set up penalty systems to deter violations of emissions law

The European commission has started legal action against the UK and six other EU states for failing to act against car emissions cheating in the wake of the “dieselgate” scandal.

VW was forced to recall nearly half a million cars from the US market last year after it was revealed that the company had used sophisticated “defeat devices” to game emissions tests. Other manufacturers have also used techniques to give lower emissions readings in lab tests than in real world driving.

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A new article helps scientists communicate how humans are intensifying extreme weather clearly and accurately

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There are no longer any reputable scientists who disagree with the principle view of that human emissions will cause climate change that will lead to societal and human losses (they already are). So, I use the term “win” here not to indicate it was a battle of “us” versus “them”. Rather, I mean “win” in that we have faithfully followed the scientific method, explored alternative hypotheses, checked and rechecked our work, and have come to a truth that is unassailable. We’ve done our job.

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Experts argue whether electric cars are worse for the environment than gas guzzlers once the manufacturing process and batteries are taken into account

Jorge Cruz has just finished his overnight shift stacking shelves at Whole Foods in Los Altos, California, and is waiting at the bus stop outside. Like much of Silicon Valley, there’s a regular flow of Tesla, BMW, Nissan and Google electric cars that cruise past from their nearby headquarters, and Cruz rather likes them.

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Ancient water channels in Morocco, declining Arctic sea ice and the US-Mexico border were among the images captured by European Space Agency and Nasa satellites last month

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Chief Scientist Alan Finkel's report into the energy sector says the Paris agreement targets may not be met.

Independent review shared with agriculture ministers in May calls for an urgent $38m eradication of invasive insects

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An independent review into the ant, which is of South American extraction, prepared for a meeting of federal state and territory agriculture ministers in May but made public this week through the Senate, calls for a doubling of funding to $38m a year for 10 years to eliminate the scourge for good.

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The world’s tallest animal is at risk of extinction after suffering a devastating decline in numbers, with 40% of giraffes lost in the last 30 years, according to the latest “red list” analysis.

The authoritative list, compiled by the International Union for the Conservation of Nature (IUCN), has also added over 700 newly recognised bird species, but 13 of these are already extinct.

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The skylark’s summer song is reduced in winter to spits of rage, each broken chirrup rendered to human ears as “get lost!” or something far ruder. Such angry chatter broke the stillness of a recent frost-becalmed morning in the fields. The strident cries told of an aerial dogfight.

Related: David Adam on the decline of Britain's skylarks and other bird species

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Red fire ants could wreak more damage than rabbits, cane toads and foxes combined, experts warn.

The market is now pricing wholesale electricity contracts for next year at levels higher than what prevailed when the carbon price was in place.

QUT engineers mimic the design of a fly's eye to create a nano-material that could significantly boost solar cell efficiency.

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In a 58-page report that has been circulated before Friday’s Council of Australian Governments meeting between the prime minister and the premiers, Finkel has also given implicit endorsement to an emissions intensity trading scheme for the electricity industry to help manage the transition to lower-emissions energy sources.

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It's obvious there is not much rational thought in some quarters of the conservative parties, and Malcolm Turnbull will come to regret his change of tone on climate change just as Kevin Rudd did.