Sharks!

How do we provide an environment safe from Sharks for recreational surfers and swimmers in WA’s south west? Can Sharks and people co-exist safely? 

 Ideas 

  • Artificial wave pools
  • Magnetic shark repelling 
  • Camouflage wet suits and surf boards 
  • Sharkbanz 
  • The Clever Buoy 
  • Shark Eyes 
  • Culling 
  • Spray shark repellents  
  • Don’t swim at dusk or dawn. 
  • Shark shield  
  • Shark stopper  
  • Use dorsal the shark app 

Gather information about the problem 

Humans are unable to completely co-exist safely with sharks at the moment as there are no solutions that don’t affect either humans or sharks negatively or are 100% effective 

Consult parents or any experts you know

Craig Anderson  (Jett’s uncle) created The Clever Buoy which gives off sonar signals to detect the distinctive movement patterns made by sharks, and transmit a signal to alert lifeguards, who can raise the alarm warning beachgoers and swimmers. 

What is causing the problem? 

Sharks being apex predators causing their natural instincts to investigate humans when they are swimming because sharks can’t tell the difference between humans and seals.

Why do we need to solve it? 

So that people can feel safe in the ocean and prevent shark attacks. We also need to develop a solution that also causes no harm to marine life and lets humans and sharks coexist safely. 

Have others tried to solve it? And how? 

Lots of companies have come up with different solutions and products to prevent shark attacks and keep people safe from sharks whilst surfing or swimming in the ocean. These include inventions like the Clever Buoy, Shark Eyes, camouflage wet suits and surfboards, Sharkbanz, magnetic and spray shark repellents, apps showing shark sightings and culling. 

How is it solved in other countries? 

There are a range of shark attack prevention techniques employed to reduce the risk of shark attacks and keep people safe. They include removing sharks by various fishing methods, separating people and sharks, as well as observation, education and various technology-based solutions. E.g. In South Africa the  

SharkSafe Barrier successfully bio-mimics the visual effects of a kelp forest, and combines this with a series of permanent magnetic stimuli, to form a barrier that dissuades sharks from passing through. The SharkSafe Barrier can be the first 100% effective eco-friendly technology to protect humans from sharks without harming the marine life. 

Can we combine or improve existing solutions?  

  • permanent magnetic stimuli inside surfboards to repel sharks away from surfers  
  • shark nets on more beaches around the south west of Australia 

 Can we combine or improve existing solutions

 

There are already many solutions that would be able to adapted to WA southwest. Our idea is to start producing similar technology that is in Sharkbanz but integrate it into a surfboard to if is less of a hassle to carry etc.

 

Our main idea is to adapt the magnetic shark barriers that are being developed in South Africa to the south west of WA. This would provide an area safe from swimmers and surfers with out the interference of a physical shark net for surfers. Unlike physical shark nets this technology could be adapted to be mobile so it could move to where the best surf is everyday making it even more beneficial for surfers.

Co-existing with Sharks

How do we provide an environment safe from Sharks for recreational surfers – swimmers in WA’s southwest? Can Sharks and people coexist safely?

What our idea is,
Our idea is to have buoys across WA’s south coast that will let off a smell, safe to the environment. It will protect surfers as well as all people in the water and will hopefully make the amount of shark attack cases smaller. This solution will be cheaper than other solutions. eg, shark nets, wave pools, trackers, etc. Our idea is to have buoys that can release a smell that sharks do not like and will cause them to swim away. To keep the smell available, there will be many groups along the south coast of WA that go and check each buoy, making sure it has enough of the smelling substance (assuming it is a gas or liquid). The groups will go out and check the buoys and make sure they are up to standards. The way it works is simple. Sharks use electroreceptors under their snout to detect potential food sources. The idea is to 'overload' their sensory system with a non-lethal electrical field that causes their receptors to spasm, forcing the shark to swim away to avoid the discomfort.

Why do we need to solve it? 

We need to solve it because as more people come to swim/surf on the beach, the chance of a shark attack increases. We also need to fix it because we need to come up with a solution that is environmentally friendly so that underwater ecosystems won’t be affected.

Have others tried to solve it? How? 

  • The SharkSmart WA app combines shark activity information by providing near real-time information of shark activity including current alerts and warnings
  • Shark deterrent: While Shark Shield can deter a shark from attacking, it won’t do so every time. The most recent study of the device by scientists at the University of Western Australia (UWA) found it prevented great whites and tiger sharks from attacking most of the time, but it wasn’t always effective
  • Beach enclosures: A beach enclosure is a protected swimming area featuring a physical barrier to reduce the risk of a shark encounter. The barrier aims to prevent sharks from entering an enclosed area and covers the full water column (anchored to the seabed and connected to floats at the surface)
  • Beach and aerial surveillance: Surf lifesavers are watching from the beaches, on the water, and in the air and public officers are ready to respond to sightings. Swimming between the flags at patrolled beaches means that if a shark is sighted, the information will be communicated quickly to the front line responders and the beach can be closed by lifesavers

Smells

Smells sharks will swim away from include certain copper compounds, such as copper sulfate and copper acetate, in combination with other ingredients, which mimic the smell of a dead shark and drive live sharks away from human beings in the water.

The sharks smells this substance, which causes them to swim away
ProsCons
Easy to use because they won’t require attention all the timeMight not be 100% effective
Can be used for long periods of time, may not need replacingEven though it is cheap, it could be difficult to fund enough buoys for all of WA’s south west coast
Cheaper and more efficient than other solutionsThe area that it protects might not reach very far so more buoys would be needed
Won’t harm the environmentWould be difficult access to check them every week or so to ensure they are functioning correctly
We needed to consider the pros and cons to see if this solution was the best and we decided the pros outweighed the cons

How will the buoys work?

The way it works is simple. Sharks use electroreceptors under their snout to detect potential food sources. The idea is to ‘overload’ their sensory system with a non-lethal electrical field that causes their receptors to spasm, forcing the shark to swim away to avoid the discomfort. 

Basically the buoy works by putting a smell in the ocean of a certain copper which sharks will swim away from, this will also be eco-friendly as it wont won’t put too much of the smell in the ocean so it won’t ruin the ecosystem.

We started by having a look at already existing buoys and discovered that they are battery powered and only last around 6-10 hours. So we came up with the idea to have them solar powered because it is environmentally friendly and is a simple way to keep them charged. 

Although we did learn that they may not be 100% effective but in addition to the other things that are already in place, it is sure to make a difference.

This is what a repellent buoy could look like
Our solution we hope can make a change and provide an environment safe from Sharks for recreational surfers/swimmers in WA’s south west and allow Sharks and people coexist safely, whilst also maintaining the underwater ecosystems.
Written by Lily, Ava, Olivia, Camden & Rafael

Cane Toads

Our Issue - How can we prevent cane toads from entering and destroying natural fauna in the Kimberly

History of cane toads in Australia 

Cane toads were introduced into Queensland in 1935 in hopes to control cane beetles which were destroying sugar cane crops. They had previously been successful in to other countries, including Hawaii, to control the beetles. 101 cane toads were brought to Queensland from Hawaii and bred rapidly. 3000 toads were released later the same year. They were quite unsuccessful in controlling cane beetles. However, they have been successful in spreading across Queensland, to New South Wales, the Northern Territory and Western Australia. Since then, they cane toads have colonised much of northern Australia and first appeared in the Kimberley region of Western Australia in 2009. Cane toads are a declared pest and pose a serious threat to native wildlife due to their toxicity when consumed. Many native predator species have declined in the wake of the cane toad invasion.

Why are Cane Toads a Pest?

Poisonous:
Cane toads are toxic at all stages of their life cycle, as eggs, tadpoles, toadlets and adults. They have been a prime contribution to many decline and extinction of many native predator species in a few parts Australia such as the Northern Territory and Queensland, including the northern quoll. Cane toads produce a toxin is strong enough to kill most native animals that normally eat frogs or frog eggs. This includes birds, other frogs, reptiles and mammals. They are a risk to both native animals and pets. 

Predatory:
Cane toads eat almost everything that is possible for them to digest this includes household scraps, meat and pet food. The main food source is eating living insects in large quantities, including beetles, bugs, honey bees, ants, winged termites, and crickets. Cane toads are also able to eat some larger animals like native frogs, smaller toads, small mammals and snakes. 

Adaptive:
Cane toads can thrive in a wide range of habitats. They thrive in urban and disturbed areas. They can also breed quickly which allows them to rapidly colonise and dominate an area. Cane toads can survive temperatures from 5-46°C. They prefer fresh water but can tolerate salty water for short periods of time, they’ve even swum from the coast of the Northern Territory to inhabit small islands. 

Competitive:
Cane toads compete with native species, for both food and habitats. They can digest a large variety of foods, this depletes the food source for many other animals. Native frogs are the most vulnerable to the threat of cane toads. 

An agitated cane toad emitting toxins (white material) from parotid gland. The toad will position itself so it cannot only ooze, but squirt (short distance) toxins at the attacker. Picture from freewebs.com/cane-toad/impact.htm
CT2 adult labels NSW DPI brochure

How is Native Fauna Being Destroyed?

A number of studies suggest that Cane Toad tadpoles may impact on the growth and survival of native species through competition for food. Cane Toad tadpoles significantly affect the ornate burrowing frog tadpoles, probably as a result of the overpowering competitive ability of Cane Toad tadpoles, rather than predation of early life stages of the species .

Cane toads compete for food with, and eat, Australian native species, including frogs. For instance the rainbow bee-eater is now endangered as cane toads eat their nesting chicks. Scientists are concerned that there could be an impact on the number of honeybees, which are also part of cane toads’ diet. If this happens, native flora would be affected as flowers depend on bees for pollination. 

Cane toad eggs are toxic. They are poisonous to fish and the toxins released into waterways cause water to become toxic as well. Native animals that eat cane toads die almost instantly when they bite into them. These native predators include: quolls, frilled necked lizards, goannas, some snakes and even crocodiles. After the cane toad front has passed through a habitat, some of its animals, particularly quolls, have become threatened species in that area. 

Cane toads in most life stages contain a poison called bufotoxin which is toxic to animals that eat them. Bufotoxin contains a number of different poisonous chemicals, including bufagin and bufotenineBufagin stimulates the heart, causing increased pulse, ventricular fibulation and cardiac arrest. Bufotenine is a hallucinogen that causes psychedelic effects. Small toxic molecules of these poisons can be absorbed directly into the blood stream of predators, from their mouth tissues.

What have people tried/currently doing to control cane toad populations?

It is possible to control cane toad numbers humanely in a small area, such as a local creek or pond. This can be done by collecting the long jelly-like strings of cane toad eggs from the water or by humanely disposing of adult cane toads. Control is best at the egg or adult stages because cane toad tadpoles can easily be confused with some native tadpoles. This approach to cane toad control requires ongoing monitoring of the creek or pond. Fine-mesh fencing can also assist in keeping cane toads from ponds that are in need of special protection. 

Researchers in Australia are beginning to understand the toad’s impact on native fauna and to appreciate the ways in which native species are adapting to the presence of cane toads and recovering from the impact of their arrival. Protecting our most vulnerable native species on a local scale is the focus of current planning around cane toads. 

Daniel Florance from the University of Sydney has found a clever way of corralling the cane toad invasion. He realised that humans have continued to give the toad a hand, long after we first brought them to Australia. By creating dams and troughs, we provided the toad with watery staging grounds that allowed it to spread across otherwise impassably dry land. By blocking the toads from these hubs, we could prevent them from spreading over 857,000 square kilometres, an area of land the size of PakistanFlorance fenced off these artificial water sources in the Northern Territory during the dry season, when temperatures can regularly climb as high as 37 degrees Celsius. He used wire and metal posts to prevent the toads from jumping over, and buried cloth to prevent them from digging under. Once the barriers were set up, Florance evicted all the toads within them, more than 2,000 in total. The fences worked. In the following months, Florance couldn’t find any toads within the protected areas (although he found several that died at the fences, trying to get in).  

Our Possible Solutions

Our group has researched and come up with multiple solutions for our issue, all of which restrict impacts and damage on native wildlife. These include:

  • Monitoring ponds and lakes in the area, collecting cane toad eggs (egg disposal). This would have to be done every fortnight  to ensure fresh water sources don’t become toxic.
  • Using cane toad poising spray.  It anaesthetises toads within seconds, and kills them humanely in 30 ‐ 60 minutes.
  • Put little mesh fences around the pond to stop cane toads entering the area (these fences have to go underground as well as they can dig) 
  • exposure to carbon dioxide is the most used method for killing multiple cane toads at a time. This method must only be used by trained operators using appropriate equipment. Place the cane toads in plastic garbage bags and fill the bag with carbon dioxide gas from a
    compressed gas cylinder. The cane toads should be exposed to carbon dioxide gas for a minimum of four hours, when in temperatures near to 32 degrees Celsius. Cooler temperatures may require exposure times longer than four hours.
  • Scientist take the DNA found in toad’s could be converted into a beweapon to wipe cane toads out, this can be injected into them making them feel sick and then die.  
  • A ditch that surrounds fresh water sources and is big enough for cane toads to get stuck in. This ditch would have chemicals that kills the cane toads and doesn’t affect any other animals.  This wouldn’t affect similar animals such as frogs and regular toads as the DNA wouldn’t be affected and they can job a lot further than cane toads.

Interesting Cane toad Facts

  •  Females are bigger in size than males
  • They are nocturnal 
  •  Cane toads don’t drink water, they absorb it 
  • They a produce a toxin called ‘bufotoxin’ this disturbs the normal functioning of the heart
  • Bufotoxin is produced in the parotid glands on the shoulders and in smaller glands on a cane toads back
  •  If an animal eats a cane toads, it would generally die in around 15 minuets 
  • If a cane toads toxin is exposed to humans there aren’t any fatal affects except if exposed to a eye it may result in blindess
  • They are solitary during the night
  • Mating season is usually after the rainy season
  • Cane toads reach sexual maturity at the age of 1 year
  • They live up to 10-15 years in the wild and up to 30 years in captivity

BY ANNIE, ELLA, RILEY & DAVID