Tag Archives: sharks

The High Price of Peace of Mind

We Aussies love our beaches – in the warmer months the coastline has a magnetic pull, drawing us to the sand, sea and surf in our thousands.

But while the thought of a refreshing ocean dip might be appealing, the concept of potentially coming face to face with one of our most feared predators has prompted officials to take drastic action.

Shark nets have been deployed off the shoreline of the east coast for more than 80 years.  But they offer a false sense of security.  Stretching less than 200 metres long and extending down only 6 metres, these mesh barriers are at best a deterrent and certainly don’t make beaches attack proof.

Sharks can get under, over or around them, and as it turns out, more are caught on the shore side of the net when they’re heading back out to sea, than when they’re swimming towards shore.

The holes in the mesh are around 50 centimetres across – large enough to let small animals pass through, but the perfect size for trapping bigger species.

Turtles, dolphins and rays are common victims of the nets – becoming entangled and drowning or starving to death.  A major concern is the ensnaring of humpback whales on their journey back to Antarctica after their annual breeding season in the tropics.

Calves in particular are easy prey – in just over a decade 55 have been caught in the shark nets, including one off Noosa in late September this year.  Another swam down to Sydney with the remnants of a Queensland net still wrapped around its mouth.

But the toll on the animals targeted by these barriers is far greater. In 2017 alone, more than 500 sharks were caught in the nets off Queensland – 377 died, more than 100 others had to be euthanised – only 20 were released.

Amongst the victims were grey nurse sharks which are classified as critically endangered and pose no real threat to us.  The vast majority of species share the sea quite peacefully with people – only a handful of sharks are responsible for fatal attacks on humans.

Just to put it all into perspective, on average one person a year is killed by a shark in Australia, as opposed to 5 dying from falling out of bed, 10 struck down by lightning or perhaps the most sobering, more than 1,100 taken on our roads.

Shark attacks are extremely rare and there is no scientific evidence to prove that nets protect humans.  What we do know is the attempt to keep us safe is killing marine life indiscriminately.

Removing so many animals, including apex predators, will have an impact on  local marine ecosystems – but we won’t be able to calculate that cost until far too late.

Marine biologist, Holly Richmond, feels so passionately about the need to remove all nets, she’s created a video:  www.thesharknetfilm.com

Ocean Life Education is passionate about protecting all marine animals and focusing on the important role sharks play in our oceans.  For more information about our programs including our Shark Discovery presentation visit: https://www.oceanlifeeducation.com.au/programs/

 

A Shout out to Sharks

They are the most feared, yet the most misunderstood, of all marine animals – apex predators that pre-date the dinosaurs by an estimated 200 million years.

Of the almost 500 species of sharks swimming in our oceans, only a handful are the complex killers we hear about on the news – the majority have a far more sensitive side.

The reality is sharks don’t have a mean bone in their body… in fact they have no bones at all! Their skeletons are comprised of cartilage which is flexible and lightweight – allowing some to reach speeds of close to 100 kilometres an hour.

But while their sleek, race car bodies have helped them to survive for so long, ironically, it is also contributing to their downfall. Shark cartilage is used in beauty treatments and alternate medicines – a part of the reason 100 million of them are killed every year by humans.

It seems we have a love/hate relationship with these fish – while movies like Jaws are enough to keep some of us high and dry on the sand during a trip to the beach, others go to great lengths to absorb nutrients from sharks, adopting an eat or be eaten approach.

Shark fin soup is a delicacy in Asia and demand for the prestige product has led to the decimation of some species including the scalloped hammerhead. The process of removing the dorsal fin from a live animal is illegal in Australian waters, but the practise is difficult to police.

But what many of us miss in our obsession with sharks, is some of their truly extraordinary abilities. Unlike humans, they breathe through gills, so their nostrils are purely dedicated to smelling. Their sense is so refined, they can detect one drop of blood in 100 litres of water. Even more astounding is they can identify which of their two nostrils picked up the scent to determine the direction to swim to track their prey.

But it’s not just smell they’re tuned into – their ability to pick up on electrical impulse and vibrations is so acute, they can sense a Double A battery from 3 kilometres away. And while these skills are designed to help them locate food, some species can survive for up to 3 months between meals – the ultimate fasting regime!

Apart from their unparalleled skill in sensing their next feast, sharks are also well equipped to chow down their catch. They are known for their multiple rows of razor sharp teeth – and it appears they have an endless supply. While humans have one set of large teeth to last a lifetime, many species of sharks can grow tens of thousands, quickly replacing any that have gone blunt and fallen out.

And while this may seem terrifying to us, the reality is we are not on their menu. Attacks on humans are generally a case of mistaken identity – surfers are the most common target, mimicking the shape of a seal on the surface. While it may be of little comfort, statistically, you are more likely to be killed by a falling coconut or a flying champagne cork than to be taken by a shark.

Ocean Life Education runs a Shark Discovery program that helps to separate fact from fiction when it comes to the most feared fish in the sea. It is one of our most popular presentations as we explore all the fascinating features that make these apex predators such effective hunters yet strangely vulnerable at the same time.

When all the hype and hysteria is removed, it is easy to see how sharks play a vital role in maintaining balance in the marine eco-system. Deep down, (and also on the surface of their snout!), they really are quite sensitive.

Shark nets, clever buoy, and protecting our beaches

Source: www.nsw.gov.au

Source: www.nsw.gov.au

Sharks, shark attacks and shark nets. You’ve probably heard the conversation in the media in recent times as our nation figures out a solution to ‘protect ourselves’ from a shark encounter.

In response to a number of shark confrontations along the NSW northern beaches (including popular spots Byron Bay and Ballina) the NSW government has carried out a comprehensive review on deterrent and detection methods to improve swimmer and surfer safety.

Ocean Life Education has long now been an advocate of education for public safety in and around our waterways. What we aim to achieve in our programs like our Shark Discovery, is a deeper understanding of sharks; the safest time and places to swim and why we sometimes come into contact with sharks.

As a long-time sceptic of the effectiveness of shark nets that are reported as protecting our popular beaches, I am delighted to see that the NSW government is reviewing both deterrent and detection methods for their northern beaches, which means that shark welfare is being considered as part of their review process.

The review mostly focuses on results of the effectiveness of such methods on the Great White, Tiger and Bull Whaler sharks and includes fourteen deterrent strategies and three detection strategies.

Review of deterrent methods

Of the deterrents, four involve electric and electromagnetic nets, ropes and cables; three are barrier nets (non-entanglement nets); five are various personal devices (worn by surfers or swimmers); a bubble curtain; and the Smart Bouy system (similar to a drum line but with capability to alert when a shark is caught so it can be quickly released).

The results showed the barrier nets were most effective, however the trials for these nets were carried out in Western Australia at a relatively protected beach where wave heights never exceeded 1.5m, therefore not a great indicator for open East Australian beaches that can have six-plus meter waves.  Not only that but keeping the barriers clean of fouling was another concern.

The electronic devices were problematic to other animals’ sensory abilities and also problematic to humans with heart problems who may use pacemakers. Personal devices varied in effectiveness but deemed not practical to protect great numbers of people at large beach sites. While the bubble curtain is an unobtrusive idea to humans and animals alike it wasn’t highly effective at deterring sharks.

Finally, there was the Smart Buoy which is just a baited drum line, with ability to alert it’s managers of a hook up, allowing the shark to be relocated. The problem here is using a baited hook brings sharks in and catches them, but also dolphins and turtles get caught too, plus staff managing relocation of animals need the right equipment and training to relocate effectively.

Review of detection methods

There were three detection methods trailed: shark spotter program; clever buoy; and tagging and real time tracking of tagged sharks.

The shark spotter program proved the most effective method of detection, the only problem is the shear expanse of coast line that needs to be monitored along the NSW north coast, which would incur a large expense.

Tagging and tracking sharks has been used by scientists for a long time now, it is effective in tracking sharks’ movements but not practical in being able to tag all sharks. Thus, this strategy rated low on the review.

Of great interest was research into technology such as the ‘Clever Buoy’, a collection of detector buoys, using sonar technology to detect large moving objects, which then sends a signal to a shore base to advise swimmers (for example a life guard tower). This detector method would keep swimmers safe and prevent the death of any marine life. It’s a win-win situation in my books.

Watch the video by Optus about how the Clever Buoy technology works.

The review did mention that this was in trial phase and needed tweaking, but with increasing technology improvements, this kind of protection for beaches is three to five years away and is both a good result for swimmers and the environment.

Final word

In 2017 we can say keep an eye on the future, it looks bright. It is great to see an improved environmental approach to an ongoing problem of humans living in harmony with the marine environment. If NSW adopts this technology and proves its effectiveness we hope that Queensland will follow suit.

Richard Coward, Director of Education

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Richard features on Ten’s Totally Wild to talk Sharks

Richard talking sharks on tens totally wild show

At Ocean Life Education, we love to talk about Sharks! We think public education is key when it comes to safety in the water and in understanding these commonly misunderstood predators.

We recently teamed up with Channel 10’s Totally Wild to clear up some of these common misconceptions.

In this segment, we look at why people encounter sharks, why sharks make mistakes and how best to avoid contact with sharks.

Sharks are important to the marine ecosystem. Without them, the ocean’s ecosystem would collapse so we need to learn to live with them to maintain a healthy ocean.

Catch Richard on Ten’s Totally Wild below. Skip forward to 1.54secs – there’s some really cool info in here and we’d love to hear from you below about what you thought, or even what you learnt!

WATCH NOW: http://tenplay.com.au/channel-eleven/totally-wild/season-23/episode-86

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If your students love sharks, you can book our Shark Discovery program for vacation care where we talk more about all of this and more!