The members of the trout and salmon family that we seek in the Great Lakes and their tributaries depend mainly on their sight for feeding.
Other Great Lakes predators like smallmouth bass, walleyes, and muskies are also mostly dependent on their vision for finding prey. The sense of smell and the feeling of vibrations also come into play, but we are going to concentrate on the visuals in this article.
Lots of factors affect how well fish see.
For sure, clarity of the water is key.
Turbidity in the form of suspended sediment particles or algae (plankton) can severely diminish the ability of the fish to see. Stained water from the presence of tannins can also reduce visibility.
The amount of light penetrating the water is very important in determining how well the fish can see your lure. Light penetration is greatest when the sun is high overhead, and its rays are perpendicular to the water surface. The lower the sun is in the sky, the more of its light will be reflected rather than absorbed.
Wave action also decreases light penetration by causing more light to be reflected.
In rivers, riffled surfaces decrease the amount of light penetration reaching the depths.
Many things affect the light before it reaches the water surface.
Clouds and fog are among the most common atmospheric conditions that can decrease the available light. In rivers and the shoals of the Great Lakes submerged plant growth can darken the water. Also on streams, shade from trees, other plants, and high banks can diminish the light.
Of course, manmade structures like docks, piers, road bridges, and, in urban areas, even tall buildings also shade the water.
As we all learned in school, sun light is made up of many colors which represent different wave lengths. It is obvious that lure manufacturers are well aware of this with the plethora of finishes available on our favorite offerings.
The wavelengths of light that are absorbed versus those that are reflected determine the color of an object. White reflects all light while black absorbs all wavelengths. A red lure reflects the red wavelengths and absorbs enough of the others so that it appears red.
The fact that different wavelengths of light penetrate water to different depths is usually not important when fishing most rivers, but can become really critical when fishing deep in the Great Lakes.
In the visible range, red light penetrates the water to the shallowest depth, about 15 feet on average. Going through the rest of the spectrum, average penetration depths are as follows: orange, 20 feet; yellow, 45 feet; green, 65 feet; blue, 110 feet; and violet, 70 feet.
Infra-red light doesn’t penetrate into water at all and, surprisingly, the average depth of penetration of UV light is only about 10 feet. However, near UV light, that which is just out of the visible range can penetrate up to 60 feet.
What this means is that if you run a red lure at a depth of 30 feet, it will appear black or dark brown because no red light can penetrate to that depth. A blue lure remains blue to the greatest depth and that explains why it is a very popular color for Great Lakes lures. This also explains why deep, clear lakes appear blue in color.
Fluorescent pigments are brighter than regular colors and they make it possible for a red lure to still be bright red at 30 feet down.
Fluorescence is defined as the emission of light by a substance/finish that has absorbed light or other electromagnetic radiation of a different wavelength. The most striking examples occur when the absorbed radiation is in the UV region and thus invisible and the emitted light is in the visible region of the spectrum.
It is important to note that blue light can activate a fluorescent orange pigment because of its shorter wavelength.
There will be situations when reflective light is severely limited and your lure needs generate its own light. Luminescent or glow in the dark finishes have been around for a long time. The luminescence is usually achieved through phosphorescent paint or plastic lure tape.
The finish must be activated with the sun or artificial light. In the past the glow would only last ten minutes or so but some of the newer finishes glow significantly longer before they must be recharged by exposure to light again.
There are also lures that accommodate chemiluminescent light sticks that glow for many hours when activated. You can also purchase lures that contain battery operated lights. Both types are a special help when trolling at night or other low light periods, very deep, or in murky water.
Chinook salmon and walleyes are prime examples of game fish we chase that are especially active during low light periods so having lures that they can see fills a big need.
Recently there has been a lot of interest in ultraviolet (UV) light and fishing lures.
UV light is by definition, invisible to man but some wavelengths may be seen by animals and fish.
Normally we think of UV light as something to avoid. We protect our eyes by wearing sunglasses and long billed caps. Likewise, we keep our skin covers and wear sunscreen to prevent sunburn and decrease the risk of skin cancer. Sunscreens may contain organic compounds that absorb the UV radiation or inorganic compounds that block or reflect back the UV rays.
Obviously if we want our lures to reflect UV light we need to use blockers.
Compounds with these properties have been incorporated into both clear coats for lures and scent solutions. There is proportionately more UV than visible light during the low light periods—dawn and dusk and when there is heavy overcast. So these times are prime ones for using lures with UV reflective coatings. Low light times are also good ones for using lures with fluorescent finishes since UV rays are prime activators of these special pigments.
It should also be remembered that it is important to not use UV reflecting clear coats over fluorescent finishes on lures.
Since you are bouncing back UV light you might diminish the activation of the fluorescent colors. Since recent research has cast some doubt on how well adult fish actually see UV, I think the activation of fluorescent colors is a lot more important in getting the fish’s attention than reflecting UV light.
Another caution is the fact that UV light is quickly extinguished by turbidity or muddiness. So don’t expect UV coating to work as well when runoff, silt, plankton blooms, or something else turns the water almost opaque.
Surprisingly, red light tends to penetrate best when the water is muddy.
Black is another good finish to try when visibility is down to a foot or less.
Of course, when the water is really dirty it is probably time to rely more on scent and vibration and a nearly stationary offering for the fish to find.
There is quite a difference in the visibility of the various metals and metallic finishes used on lures.
Real silver plate stands out when it comes to getting the fish’s attention. Silver reflects the most light of all metals, something over 90 percent, and it gives off a very white flash since it is reflecting most of the wavelengths of light that strike it.
Real gold is next, reflecting a percentage of light in the mid-80s. It obviously reflects the yellow wavelengths best, giving it the color flash that it has. Copper and brass, which is a copper and zinc alloy, generally reflect between 70 and 80 per cent of the light that strikes their surfaces.
Nickel and chromium are at the bottom of the list in their ability to reflect light, generally around 60 per cent or less. Their flash is rather dark as well since they are bouncing back a lesser amount of light.
It has been interesting to watch the metallic finish on spoons trolled deep in the Great Lakes evolve over the years. Initially most were nickel plated but now the vast majority of those in use are real silver.
There is no doubt that silver spoons are much more visible where available light is at a premium.
Usually we are striving to make sure our lures are visible to the fish but it is possible for them to be too gaudy for the conditions. We definitely want the fish to notice our offerings so they can’t be too small and inconspicuous.
But if we are trolling shallow in the spring or fall on the big lakes or the stream is ultra clear and the sun is bright, a large, fluorescent and silver lure is probably not the best choice.
It is definitely possible to spook or turn off the fish by using a lure that is too large or visible for the conditions.
As an example, when I am fishing for trout in a small stream with spinners, I will purposely use a small tarnished brass bladed lure when the creek is low and clear and the sun is bright.
Conversely, if rain roils the stream I will switch to a steelhead sized spinner with a silver blade so that the browns can find my lure.
A final tip for making your lures more visible is to use lures with contrasting finishes. If your favorite lure doesn’t come in contrasting colors, you can easily customize your offerings using lure tape.
Most of the time I modify my silver steelhead and salmon spinners by using two colors of fluorescent tape.
Most commonly, I will apply both fluorescent yellow and orange tape to the back of the blade. I will also use two different colors of tubing on the treble hook. The tape itself, even if just one color, will also contrast with the metal blade.
As the spinner approaches the fish, the steelhead or trout will mostly notice the flash of the blade. Then as the lure sweeps in front of the fish it will change from a flashy one to a glowing fluorescent spinner when the predator sees it from behind.
Most lures used by Great Lakes trollers are multicolored with shades that often are very different. This was very evident in Dave Mull’s article on spoon patterns in the February/March issue of GLA. A number of the finishes were rather dark and would not seem to be very visible when trolled deep in the Great Lakes. However, these dark colors probably contrast very well with the metallic silver side of the spoon.
It is obviously very possible to customize big lake spoons and plugs with lure tape. I remember when black “ladder backs” were the rage on J-Plugs. The contrast made them more visible but some of us decided they were on the wrong side of the plug. Since salmon usually attack their prey from below, we switched our lures to ones with “ladder bellies” and did well.
As you select lures to use in the Great Lakes and their tributaries keep in mind the need to make sure they are visible to your quarry. And, remember it is possible that lures that are too bright or large for the conditions may turn off or spook the salmon, trout, steelhead, walleyes, and smallies you are trying to catch.
- Written by Jim Bedford