Sharks appear to dislike the noise of the bubbles scuba divers create as they breathe underwater. One researcher also found that playing the AD/DC song "You Shook Me All Night Long" did not repel sharks, but did seem to calm them and make them less aggressive, perhaps because they were curious about the sound.
Because sharks have been successfully hunted and attacked by killer whales, Wynne's idea is to use the sounds of killer whales mixed with high frequencies (below 500 hertz) to scare sharks away.
Natural repellents
The Pardachirus marmoratus fish (finless sole, Red Sea Moses sole) repels sharks through its secretions. The best-understood factor is pardaxin, acting as an irritant to the sharks' gills, but other chemicals have been identified as contributing to the repellent effect.
Just like we check under our beds for monsters, sharks check for dolphins before nodding off. That's right, the toughest kids on the undersea block swim in fear of dolphins.
Alternatively, divers and swimmers can probably reduce the chance of an interaction with a shark by avoiding bright and highly contrasting swimwear or dive gear. We personally prefer to use dark blue or black fins, mask, tank, and wetsuit while diving.
Basically, this means that in situations when personal deterrents (such as the Ocean Guardian Scuba7) do not prevent bites, shark bite injuries can be reduced through puncture-resistant fabric such as Kevlar neoprene.
Scientists say sharks may have a musical preference, and it's not for classical music. A study found that one species of the finned predator, the Port Jackson shark, enjoys the sound of jazz – when there's food on offer.
As the shark swims around you, keep your head on a swivel and try to maintain eye contact. "Sharks are ambush predators," Peirce explained. "If you're turning around and facing it the whole time while it circles you, it's not going to be half as comfortable as if it's able to sneak up from behind."
As reported by Discovery Channel, the first significant discovery was that sharks hate the smell of rotting shark carcasses and quickly swim away from the scent.
Sharks are attracted to low-frequency pulsed sounds, similar to those wounded or ill prey would emit. Most attractive sounds are in the frequency range of 25 to 100 Hz. Some sharks are attracted to sound sources from distances as great as 250 m (820 ft.).
The most effective personal repellent currently on the market is the Freedom + Surf, which has been shown to repel both white sharks and bull sharks. But even so, it only reduces your risk of being bitten by about 60% – and the sharks may still come close!
Magnets repel sharks, studies show, by interfering with their ability to sense electrical fields. A recent study shows that magnets placed on the nets can repel sharks and rays from entering the trap. Shark-repelling magnets may be the perfect antidote to unwanted shark attention while fishing.
Be aware that activity which might imitate a prey animal in distress — such as splashing, slapping the water, and screaming — might attract sharks.
Shouting into the ocean, blowing bubbles, slapping the water, and throwing paper scraps into the sea will not scare away a shark.
Sharks appear to dislike the noise of the bubbles scuba divers create as they breathe underwater. One researcher also found that playing the AD/DC song "You Shook Me All Night Long" did not repel sharks, but did seem to calm them and make them less aggressive, perhaps because they were curious about the sound.
Go for the shark's most sensitive areas – its nose, its gills, and especially its eyes. Dig in and keep pressing until it lets you go. Remember that sharks will often thrash around once they have a bite, so if you can, give it a “hug”.
The market offers five main types of shark deterrents: magnetic repellents, electric repellents, sound repellents, semiochemical repellents, and visual repellents. They reach the consumer market in the form of surf leashes, rubber bands, spray cans, and wetsuits.
Since sharks see contrast colors, anything that is very bright against lighter or darker skin can look like a bait fish to a shark. For this reason, he suggests swimmers avoid wearing yellow, white, or even bathing suits with contrasting colors, like black and white.
Sharks are attracted to human blood
They can also detect blood in the water from miles away. Contrary to popular belief, however, sharks are not attracted to human blood. A shark is more likely to be attracted to a bleeding fish or sea lion than a human being with a cut in the ocean.
During an large-scale experiment called Human Shark Bait, they put two divers in water at the same time — one was holding a bottle of urine, which he slowly poured into the water. The other diver didn't bring any pee to the table. Researchers tracked the brains of white sharks as this was happening. No reaction.
Move swiftly but calmly – sharks are attracted to splashing. If the shark is already swimming at you, no need to go quietly.
“If... a shark bites you, what we recommend is you should hit the shark in the eye, in the nose, or stick your hand in the gills,” says Chris Lowe, of the California State University Long Beach Shark Lab, in an instructional video. “Those are all sensitive tissues and quite often it causes the shark to release.”
Sharks are the most active at dusk and dawn when they are hunting for food. You can reduce your risk of shark encounters by staying out of the water at these times of day. Sharks also don't have the best vision, so they will be more likely to confuse a human for its natural prey when visibility is low.