Flash In the Dark (UV Light & Fishing) by Keith Jackson

If you’ve been following tackle trends at all of late, then you’ve noticed an increasing number of lures that have UV—for ultraviolet—finishes.

Is this just the latest trend designed to catch fishermen first and fish later?

Well, it’s a long story with a lot of twists and turns, but the short version is that if you fish for salmon or trout, UV lures can improve your catch rate. And it’s likely that other species of fish are able to see UV as well.

The recent UV phenomenon probably started with commercial salmon fishermen in the northern Pacific a couple of decades ago.

Trollers often use flashers and dodgers trailed by a squid-like hoochie. These soft plastic lures look a bit like a squid and have long tentacles. They come in a rainbow of colors, but one of the more effective colors was a near-transparent clear that had a ghost-like tint of purple, especially when you viewed the tentacles edge on.

It was a UV-reflective lure that became a favorite in the sportfishing world. Soon it was apparent that ultraviolet finishes were working better than standard finishes, and more were added, and UV then moved into hard lures.

As the word slowly spread, more and more lures were produced with UV-reflective finishes. Time has proven that they work—at least for the salmon and trout tribe. 

What Is UV?

UV is shorthand for ultra-violet light, the light at the short end of the spectrum, way past blue and violet. UV light has a wavelength of 400 nanometers or less. It’s the light that penetrates the cloud layer in the atmosphere and gives you a sunburn.

While most humans can’t see UV light, many plants and animals reflect it, but not all do. Plankton, insects and fish often reflect UV, and just like visible light, it helps various critters—the ones that can see that part of the spectrum—find food, evade predators or find a mate. It’s also a strong attractant for many insects, and it’s the light source for many electric “bug zappers.”

Ultraviolet-reflecting finishes are manmade, but there are many things in nature that reflect UV light. Insects and plankton, both major food sources for young fish, tend to reflect UV. So do some fish and some birds as well, and often that is why natural feathers or fur works better in a fly pattern than another feather dyed to match the color.

Scientists think that UV in animals helps them find mates and identify others of their species. Predators tend to see in the ultraviolet end of the spectrum, generally, to help them find prey.

Which fish can see UV light?

This is where the “UV-catches-everything” trend slows down. There is very little research on which fish see this part of the spectrum, and almost none for game fish. Salmon and trout species generally can see ultraviolet, but it can and does change in some species depending upon the stage of life the fish are in.

Supposedly, Pacific salmon see in UV when they’re young and in the streams, and this helps them find food as some aquatic insects and plankton reflect UV light. However, it’s believed that the salmon lose this ability when they move to the ocean only to have it return when they’re back to spawn.

The quandary is that this doesn’t explain the effectiveness of lures with a UV finish in the ocean. But fishermen don’t care about the science as UV lures are working in the ocean, and fishermen are showing a preference.

Not all species of fish we chase have the receptors to see short wavelength light. But again, there is very little research on which do and which don’t.

Here’s an instance that might make you think.

Walleyes aren’t supposed to be able to detect UV light, or that is what some research indicates. However, several years ago, I was on a trip with a walleye pro on Lake of the Woods, and I had a couple of Long A Bombers that had a UV-reflecting finish. Originally, these were painted for use in Russia for salmon fishing.

I was playing around with UV a bit at the time, and wanted to see if it would have an effect on fish other than trout. The 15As were wrong for the fishery, the pro said, as he tied a Reef Runner on his line. We were fishing in kind of dingy water with a lot of wave action and running our baits on leadcore.

I caught fish, and he didn’t. When I left, he kept the 15As.

The question is, though, was it the lure that caught the fish, or was it the UV finish?

Why is UV Important?

For those fish that can see UV light, it’s nothing more than a visible part of the spectrum. It’s not magic, nor is it more or less attractive than green or white or orange light. It’s just there.

However, ultraviolet light can be an important factor in how visible a lure is. And that may well be the reason why UV lures are proving to be effective in certain situations, such as the one noted above.

It also may be possible that fish which feed on UV-reflecting organisms when they’re young are conditioned to strike at things that act (or smell) like food and reflect ultraviolet light.

Basically, in the example above, we were fishing in low-light conditions—running the lures 20 feet or so down in stained water with a lot of wave action, something that also filters light.

UV rays penetrate water deeper than most of the visible spectrum, and lures that reflect ultraviolet are more visible as a result.

UV rays also penetrate colored and dirty water farther than does the visible spectrum; that’s why you can get sunburned (from UV rays) on a dark, cloudy day.

So it’s possible that the 15As were hit simply because they were in the zone and more visible than the Reef Runners.

And that is part of the puzzle that fish psychologists (just kidding there, folks) have pondered. Are fish hitting a lure because it reflects UV, or are they hitting the lure because they can see it better?

A friend of mine designs soft plastic lures for a major tackle company. I asked him about UV and walleyes in particular since he was an avid walleye fisherman.

“When I pour baits for myself, particularly the white grub,” he said, “I add UV elements to it. It acts as an optical brightener, making the white really stand out.” He told me that he believed that the addition of UV to his grubs helped him catch more fish.

He added that his company does use UV additives to make colors more intense also, but they don’t specify which ones or which colors.

 

More often than you might imagine…

The addition of ultraviolet-reflecting additives to lures and finishes is fairly common. Brett Ware, president of Tightlines UV Lure Company is capitalizing on this fact. His company received 16 patents for the use of ultraviolet light finishes and pigments in fishing lures.

“There were over 28 million UV lures sold in the U.S. in 2014,” Ware said. Many of them were made by companies that are not licensed by Tightlines UV. Many of the lures aren’t marketed as having a UV finish. “Damiki is one company that does state its lures reflect UV light,” Ware says, “While Megabass uses it in its lures but does not say so.” He adds that UV is “really taking off in Japan,” which may be where it started in the first place. Yamashita, a lure company, made the UV squid that commercial salmon fishermen in the Pacific used and preferred.

There are other manufacturers adding UV finishes to their lines, and in some cases, manufacturers may be using paints or pigments that have UV components and may not be aware that they are.

Unless you’re one of those humans who can see ultraviolet light, there is no easy way to tell if a lure reflects it or not. Sure, you can hit the lights and turn on a black light, but that’s difficult to do when you’re shopping. Store managers have a thing about customers hitting the light switch.

Even then, you’ll get fluorescent finishes that reflect the black light, and while some of that may be ultraviolet light, it may not be.

The one thing you can say that if you do the black-light test, and the lure remains dark, it likely isn’t going to be UV reflective.

The End Game… 

What does this mean for a fisherman? That is an excellent question because there is no solid answer. There are too many variables to the equation.

One thing you can say, though, is that UV light penetrates the water column farther than most other wavelengths. Because of that, it gives a UV-reflecting lure better visibility in low-light situations, such as dark, near-dark, cloudy or stained water.

Generally, the salmon tribe, including trout, sees the UV bandwidth at some point in their lifecycle. Evidence from the Pacific Northwest fisheries indicates that lures or baits that reflect ultraviolet light work well, and perhaps better than those that don’t.

When you get into other species, it can be a guess whether the fish do or don’t see that end of the spectrum. Bass apparently do. Walleyes maybe do. Panfish…possibly. Crappies probably. And it’s quite possible that the young of these fish did see in UV as plankton and aquatic insects often reflect it. Whether or not the adult fish continued to have the ability is questionable.

The way this really lays out is experience will teach us fishermen which species see ultraviolet light. We’ll find out by fishing with UV lures and compare them to non-UV lures and see which works better.

Another option is to take a lure that doesn’t reflect UV light and treat it with something that does, such as a scent product.

Pro-Cure Baits (www.pro-cure.com) makes Pure UV Liquid that you can add to any scent, bait or lure. The company also makes a number of different scents and additives that include UV enhancement.

The only problem with scented additions is that you can’t tell if it’s the scent or UV that triggers a reaction.

Skeptics will continue to say that ultraviolet reflectance doesn’t play a part in whether or not fish hit a lure or bait. Proponents will argue that it can and does.

But it’s the fish that are the final judges, and all we have to do is listen to their judgment. I don’t know about you, but I can go with that.

- written by Keith Jackson