Science, Uncategorized

Shark Nets: Friend or Foe

Shark nets are a common safety precaution around Australian beaches, with the simple idea that sharks will get caught in the net and not go further into the beach, therefore, protecting the swimmers. They are in place at most popular beaches along the east coast of Australia, but do they actually keep swimmers safe? Some might see shark nets as an easy fix, but the issue is much more complex than a net can fix. Lets get one thing straight before I discuss the issue in detail; shark nets don’t stop shark attacks.

How do shark nets work?

They are a long, net system, generally 6m tall and 150m long, creating a semi barrier for that particular part of the beach. Because they don’t span the length of the beach, nor do they go from surface to seafloor, they don’t stop a shark from entering an area. The holes in the net are 50cm wide, large enough to let fish pass through while entangling larger animals. In Queensland, drumlines generally accompany shark nets, and are basically a hook with bait on it, aiming to catch the shark before it can move further towards the beach.

Shark net

A representation of a shark net, taken from the ABC Science site

In NSW, shark nets are only in place for 8 months of the year, and only 14 days per month.

Why this isn’t the solution?

A net doesn’t have any way of discriminating between animals, it is simply a pieces of rope strung together. This means that so many harmless animals get caught in these nets and die. This is known as bycatch, where non target animals such as turtles, rays, dugongs and dolphins, are tangled and killed in these nets. In fact, over 15,000 animals have been killed in these nets in NSW since they started being used in 1930.

In Queensland, this time of year is Humpback whale migration season, and the government refused to take the nets out for this period. This has resulted in Humpbacks becoming entangled in these dangerous nets three times this year!

If so many animals get stuck in these nets, many of which are endangered, there is the possibility that these nets could be luring sharks into the area. There is not a lot of proof to justify this theory, however if true, it would seem these nets are counter productive. Although in the short term, there has only been one fatal attack at a netted beach, but it will take years to find out whether these nets are truly effective.

If this isn’t the solution, then why are they still being used?

Well, the answer is somewhat complicated, but can be summed up in two words; insurance policy. If the politicians remove the nets, and someone gets attacked at a previously netted beach, there will be enormous backlash from the community to make beaches safer. So if the government puts nets there, and someone gets attacked, they can say that they put in place safety measures, and it is still the swimmers responsibility to accept the risks when they enter the ocean.

These nets give a false sense of security to tourists and locals. Even so, we always have to acknowledge the dangers that come with swimming in the ocean, but the reality is that the chances of getting attacked by a shark at an open beach is extremely unlikely, even with the nets in place.

What are the other solutions?

There are so many alternatives to shark nets due to recent advances in technology. Early warning systems are key to protecting swimmers. A shark receiver, or Clever Buoy, is one way to protect swimmers, and works by sending out a signal to lifesavers when a shark comes within a certain distance to a receiver, and they can then close the beach. This obviously only works for tagged sharks, but is a step in the right direction.

Clever buoy

* note the absence of nasty nets that would usually trap other animals

Another possibility is the use of deterrents. Some use electrical signals, (which is the main way that sharks sense their environment), to reduce the probability of an attack. It is still early days with this concept, and therefore is still in the testing phase. You can read more about this method here.

There are also apps, such as Shark Smart, which send you a notification when a shark is spotted, or a receiver from the Cleaver Buoy is triggered, so YOU can decide whether the water is safe. This is another way in which we can acknowledge the risks of the ocean.

But ultimately, we need to enhance awareness and recognition that we share the ocean with sharks. Showing people how beautiful sharks are can really change peoples negative opinions of them. You can find so many people on Instagram, sharing photos that highlight the beauty of sharks, and not their negative, media altered side. Shark Girl Maddison, Ocean Ramsey, and my favourite Matt Draper, just to name a few.

Shark Girl Maddison has also released an E-Book that explains the essentials that you should know when your surfing or swimming, and what to do if you encounter a shark in the ocean.

As always, you can send me any questions via the contact page, or you can message me on Instagram and Facebook!

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