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New tech could allow for more eco-friendly barnacle control on boats


July 5, 2013

A sample piece of hull material painted with (bottom) and without the ivermectin-laced paint

A sample piece of hull material painted with (bottom) and without the ivermectin-laced paint

Barnacles may look nice and nautical on things like rocks, but they’re a major problem for watercraft of all sorts. On the hulls of ships, for example, they can drastically decrease the vessel’s hydrodynamics, causing it to burn more fuel and emit more emissions in order to maintain its cruising speed. The most common way of keeping barnacles off those hulls involves the use of environmentally-unfriendly paints. Now, however, a scientist from Sweden’s University of Gothenburg has developed what could be a less harmful alternative.

In regular “anti-fouling” hull paints, toxins such as copper oxide are mixed into the paint. That poison gradually leaches out of the paint, repelling would-be barnacle hitch hikers, but also entering the marine ecosystem. Various research institutes are looking at the use of more innocuous substances, such as a seed-inspired coating, electrified paint, and even a twitching polymer.

U Gothenburg post-grad student Emiliano Pinori has taken yet another approach. Instead of copper oxide, he’s mixed an antiparasitic agent known as ivermectin with regular hull paint. Unlike the copper, very little of the substance leaves the paint. Instead, barnacles come into contact with it only once they attempt to penetrate the paint’s surface. They’re then poisoned, and fall off the vessel.

According to Pinori’s research, a concentration of just 0.1 percent ivermectin is sufficient to render a paint barnacle-proof, with the anti-fouling effect lasting for “many years.” While small amounts of ivermectin still do leach into the water, he is hoping to get that amount down to zero.

Emiliano isn’t the only scientist at the university who’s investigating new methods of keeping barnacles off boats. Other Gothenburg researchers have recently explored the use of bacteria-produced macrocyclic lactones, and a veterinary medicine known as medetomidine.

Source: University of Gothenburg

About the Author
Ben Coxworth An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth

I think making the hull emit gamma rays would be less toxic over all.


If the barnacles are poisoned, then their dead bodies contain some of the toxin. Meaning some of the ivermectin will always get into the environment.


@slowburn. That's all we need, giant green angry barnacles. LOL.

Still, poisoning shellfish with will become part of the aquatic food chain and poison whatever eats it, is not the answer.


re; pTeronaut

To clarify. There is no chance that gamma rays will result in FLKs because gamma rays denature DNA resulting in cell death; it does not rewrite DNA. A beam of light it does not leave toxins behind even if it is way higher frequency than the eyes can normally see.



Ivermectin is already in widespread use as a de-worming drug for humans, dogs and farmed fish. Don't assume that just because something is toxic to one form of life that it is likewise dangerous to all species.


I am not a chemist but I would guess that in nature Ivermectin breaks down faster than copper oxide.

re; Gadgeteer

Just because it kills the host slower than it kills the parasite does not mean it is not toxic to the host. From https://en.wikipedia.org/wiki/Ivermectin Toxicity and potential drug interactions

The main concern is neurotoxicity, which in most mammalian species may manifest as central nervous system depression, and consequent ataxia, as might be expected from potentiation of inhibitory GABA-ergic synapses.

Dogs with defects in the P-glycoprotein gene can be severely poisoned by ivermectin.


Ivermectin is used in farming sheep to kill parasitic insects. I lived in a sheep farming district where the ivermectin used in the sheep dip found its way into the rivers. Once there, even in tiny concentrations, it killed all the invertebrates which meant the fish had nothing to eat, so there were no fish. Paint may retain ivermectin initially, but the bonds which hold paints together degrade when exposed to weather and sunlight (just look at a harbour full of boats fading and peeling). The ivermectin will eventually be released with devastating consequences for the small sea animals which feed the fish. "Field studies have demonstrated the dung of animals treated with ivermectin supports a significantly reduced diversity of invertebrates, and the dung persists longer." So, a sea devoid of invertebrates and full of undigested excrement. No thanks.

Doug MacLeod

Ah, yes, Slowburn, ever the master of Google and always someone with a better idea on every Gizmag story.

Out of curiosity, has any scientist, researcher, corporation or inventor profiled in Gizmag articles ever adopted one of your suggestions?


I enjoy reading Slowburn to see what he can up with - this one is a beauty! Make the hulls emit gamma rays? How? Electro-plate the hulls with plutonium? And do you suggest it only for cargo carriers (less crew to die from cancer) or all boats (passengers glowing in the dark - Hey, save on lighting)? How many ports would want radio-active hulls in their harbours?

The Skud

re; Gadgeteer

I can not say they got the idea from me of course but before there was this.

www.gizmag.com/gravitylight-gravity-powered-led-lamp/25394/ GravityLight tackles weighty issue of lighting in the developing world By Darren Quick December 10, 2012

There was this.

www.gizmag.com/nomad-portable-solar-lighting-system/22263/ I would prefer to see a light without batteries but with a spring or gravity powered generator. The gravity power unit is just a weight and string on a reel. For camping and backpacking the weight could be a boot or full water bottle. Slowburn 23rd April, 2012 @ 07:20 pm PDT

re; The Skud

I was thinking cobalt 60 and only on ships with steel hull plating at least 2 inches thick. Done right and it is safe for crew and passengers. Gamma rays do not cause secondary radiation. Not that it would harm anybody in a well run port but that would be a problem. Lets go with X-rays instead. We will need a outer hull with a high transparency to X-rays and a lot of X-ray tubes but they can be turned on and off at will.


The best way to deal with fouling is to bathe ships' hulls in fresh water each time they dock. Not sure about barnacles attaching to hulls while underway but yachts that have their slips at the mouths of rivers (or up stream from the ocean) seem to be much less prone to fouling.

A system consisting of a large hull-shaped nylon bag with floating collar could be pulled under each vessel in port and filled with a layer of fresh water (until the concentration of sea water is minimal). Shipping companies would pay for this service in order to save down-time and materials costs.


The science is pretty well confirmed about Ultrasonic antifouling. Impulses varying between 20KHz and 40KHz in frequency have proved effective as antifouling, with no chemicals. This article's type of antifouling is soon to become not only redundant, but banned on environmental grounds


An electrician friend once told me that a low voltage current passing over a ship's hull would prevent fouling. I guess it could cause electrolysis of metal parts though.


Off shore Oil rigs steel frames are treated with radiation, which works well. but when the rigs life span is over there a tad bit hard to get rid of.

Jay Finke

Ross the Hz is far lower than that. In fact the effect was discovered by the navy when they were trying to find out why one patch wasn't fouled. It turned out to be a sailor rock and roll music speaker resting on the hull.

There I guess still pulse units available. Just buy the transducers and pipe the music of your choice to them. Or a pulse every .5second works too at much lower power levels.

fresh and saltwater gas different lifeforms and many die when switching as a ship goes upriver. There are barnacles for both. For best effect stay at least a week in the water you use least every few months really helps.


Superhydrophobic coating like Never Wet (assuming it lasts through a decent amount of use).


Yes WB1200, "Never Wet" does come to mind and would incredibly reduce drag to boot. However it is very expensive in the amount needed to protect boats' hulls. Try looking up it's costs, it's not cheap and not available to the public for any possible use they might dream up. Campers would love to have their fabrics treated but in spite of the product release I have yet to see it used in any product sold to the public. Something is up with that and there might be some issue/s not made public by it's producers. For such promise of applications they are not forthcoming. Does anyone know of a commercial public use?


re; Jay Finke

Look up the term "half life" as it relates to radiation. Pick something that decays to stable. This is not the right isotope to use but I don't need to look it up. highly toxic Iodine 131 decays to Xenon 131 which is a non-radioactive noble gas.

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