Changing Planet

Can a Lionfish-Patterned Suit Repel Sharks?

This lionfish-pattern “rash guard” is said to repel sharks. Does it work? Photo:

“Rash guards,” also called “rash vests” and “rashies,” may not be that well known to the general public, but they have been used by water sports jocks for years. Made of spandex and nylon or polyester, the synthetic material resembles a wet suit, but instead of keeping the wearer warm, it helps cool them off.

When wet, a rash guard serves as a kind of second skin, and as the water evaporates from it, it can help cool the body beneath. Rash guards are also designed to protect skin from harmful UV rays. They got their name because they serve as a barrier against abrasion on sand, coral, or a surfboard.

Now, an online retailer is marketing a rash guard that is emblazoned with the striped pattern of a lionfish. According to the site, it “therefore minimiz[es] your chances of being mistaken for a sea lion or any other type of favorite food on the menu of local sharks.”

The site added:

Lion Fish is not on a shark’s normal menu, and despite attempts to train sharks to eat Lion Fish, these attempts were only limited to one place off the coast of Honduras.

In addition to poisonous looking fish stripes on the surface of our Rash Guard, the large eyes placed in an unnatural location should also confuse and scare off potential predators looking for a quick bite.

(See “Pictures: Sharks Taught to Hunt Alien Lionfish“)

Will it Work?

“I seriously doubt that will work,” Bradley M. Wetherbee told National Geographic’s Ocean Views. Wetherbee studies shark ecology and behavior at the University of Rhode Island.

Wetherbee explained that animals use coloration for different reasons, including “poster-type advertising” that relies on bright colors and bold contrasts to advertise to predators to leave them alone (usually because they contain toxins), and to attract mates. “I don’t know for sure, but I would think with lionfish that their coloration is more cryptic than advertising.  Even if their coloration was advertising the sharks may not be used to lionfish since they are an introduced species,” he said.

“People spear lionfish and feed them to sharks some places where they are trying to reduce the number of lionfish since they are invasive species,” Wetherbee added.

Of course, actually testing the rash guard would be challenging. Shark attacks on people are quite rare, statistically. Dummies and cadavers would provide different signals to the highly tuned predators than real swimmers.

National Geographic reported on a study in January 2011 that found that many sharks appear to be color blind. “Our study shows that contrast against the background, rather than color per se, may be more important for object detection by sharks,” study co-author Nathan Scott Hart at the University of Western Australia said.

If sharks do rely on contrast as an important signal, then can a lionfish-inspired pattern throw them off? Wetherbee doubts it.

Zebra Stripes?

Interestingly, another company has been advertising wet suits patterned with zebra stripes as a form of shark repellent.

“Surf Lady” Veronica Grey and Boz wetsuits claim their design mimics the banding patterns on sea snakes, highly venomous marine reptiles. They write:

Can we 100% guarantee you won’t be bitten by a shark while wearing this suit? We can only liken it to wearing seat belts while driving or a helmet while snowboarding or using birth control – it is merely an enhancement that increases your chances of safety. Studies show that if you have been in the ocean, you have probably at some point been within 10 feet of a shark and never even knew it. Our shark deterring wetsuit intention is based on logic and scientific fact but we cannot take responsibility for the randomness of shark behavior.

But Wetherbee said, “Somewhere along the way someone identified sea snakes as a common prey of tiger sharks.”

Other people have tried painting their surfboards to look like orcas, since the whales are often considered enemies of sharks. It’s unclear how well that has worked.

Lionfish-pattern rash guard
Keeping cool, looking bold. Photo:

Beware Lionfish

Lionfish (see video) have gotten a bad rap in recent years, since they have become invasive in many parts of the world, in large part because of their popularity in the aquarium trade. They are predators with long, venomous spines, and they can upset fragile ecosystems in places where they aren’t native.

In addition to trying to teach sharks to start eating them (which may eventually catch up to rash guard wearers), conservationists have also been asking fishermen and anglers to catch them.

Some chefs, including National Geographic Fellow Barton Seaver, have discovered that lionfish can make a tasty, and sustainable, menu item.


Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for and E/The Environmental Magazine, and has written for Popular Science,,,, Yahoo!, MSN, and elsewhere. He is the co-author of six books, including Geothermal HVACGreen LightingBuild Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.

  • Ilya

    Here is article in Australia that seems to support idea of having rash guard to offer better chance of protection against shark attack:

  • Ima Ryma

    The horny male lionfish
    Swam up to a potential mate,
    And began his best show offish
    Efforts to obtain a hot date,
    Flaunting and boasting his buff bod,
    Shaking all his spines in display,
    But thinking to himself ’twas odd,
    She was acting in a strange way.
    Cuz the object of all this woo
    Shot away like a cannonball,
    Wearing some look like thingaroo,
    Was not a lionfish at all.

    In the ocean there are all types,
    Even weird humans wearing stripes.

  • goose

    Rash guards are not used to keep the person cold….

  • Jennifer Chapman

    Feeding invasive lionfish to potential predators has been officially and strongly discouraged by leaders in lionfish research and management.

    Lionfish spines and venom can affect fish health and have been known to cause death in potential predators. Groupers in the Indo-Pacific have evolved to know that lionfish are not a savoury prey item; we have no reason to believe that predators in the Atlantic are immune.

    Furthermore, conditioned fish-feeding creates unsafe conditions for divers, as predators become accustomed to people. This also puts the predators at a higher risk of capture by spear fishing.

    A consensus was reached amongst experts, conservationists and divers that feeding of invasive lionfish to potential predators in the Atlantic was to be “aggressively discouraged”.

  • Peter

    ‘Studies show that if you have been in the ocean, you have probably at some point been within 10 feet of a shark and never even knew it. ‘

    Oh really? Which studies? What is the likelihood that the product is effective when the company makes such outrageous fright-tactic claims? Garbage in and garbage out.

  • WICC

    The only company legally allowed to sell shark repellent rashguards is as they are the only ones who own the trademark. Anyone else using the words shark repellent is doing so illegally and promoting their products is irresponsible, like promoting bootlegged music or film. Only has done the extensive research backed with numerous TV appearances and footage.

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