Fish have several means to detect their prey. Their sense of smell is thought by some scientists to be 1 million times more sensitive than the human sense of smell. Their sense of hearing uses their inner ears and lateral lines (a row of auditory and pressure sensors down the middle of either side of their bodies) to detect both sound and vibration, which travel faster in water than in air. Fishermen remain divided over the ability of fish to see color under water and its relative importance when fishing, particularly when fly fishing. Fish do perceive color underwater, though; the following steps cover how fish can see color and how you can use color effectively when fly fishing.
1. Understanding How Fish See Color
1. Know how fishes' eyes are structured. Human retinas contain two kinds of receptor cells, rods, and cones. Rods enable us to distinguish light from darkness and to see at lower levels of light, while cones function in brighter light and enable us to see colors. Fish eyes also contain both rods and cones, allowing them to see in color, with the proportion of rods to cones dependent on whether the fish inhabits relatively shallow or deep water.
2. Understand how water depth affects light penetration. Light is divided into various wavelengths. Longer wavelengths of light, such as red and orange, are absorbed quickly in water and therefore penetrate to a shallow depth. At a depth of 10 feet (3 m), red lights is almost completely absorbed, and at 30 feet (9.1 m), orange and yellow light is mostly absorbed. Shorter wavelengths of light, such as green and blue penetrate to a much greater depth, and scatter more, explaining why bodies of water appear blue or greenish from above.
2. Understand how water depth affects light penetration. Light is divided into various wavelengths. Longer wavelengths of light, such as red and orange, are absorbed quickly in water and therefore penetrate to a shallow depth. At a depth of 10 feet (3 m), red lights is almost completely absorbed, and at 30 feet (9.1 m), orange and yellow light is mostly absorbed. Shorter wavelengths of light, such as green and blue penetrate to a much greater depth, and scatter more, explaining why bodies of water appear blue or greenish from above.
- How colors appear underwater is affected by how far away the object appears. Red objects turn gray and then black, while blue objects turn white before turning gray and finally black.
2. Choosing the Right Fly Color
1. Choose fly color according to how bright the sky is. The maxim for freshwater fishing lures is "light day, light color; dark day, dark color." This is more commonly applied to jigs, plastic worms, and crankbaits than to artificial flies, but it can be a factor with them, as well.
2. Choose fly colors according to how clear the water is. Subtle color shades, such as maroon, indigo, and purple can be effective when fly-fishing in clear water. Fluorescent orange, yellow, and chartreuse flies can be effective when fished in muddy water or other conditions when fish having a harder time seeing the fly, as can black and red.
4. Choose colors that match those of foods fish feed on. Although they are called flies, dry and wet flies may also imitate minnows and crustaceans that fish feed on.
Tips
2. Choose fly colors according to how clear the water is. Subtle color shades, such as maroon, indigo, and purple can be effective when fly-fishing in clear water. Fluorescent orange, yellow, and chartreuse flies can be effective when fished in muddy water or other conditions when fish having a harder time seeing the fly, as can black and red.
- Fluorescent colors are more effective in muddy water and on cloudy days because they are made brightly visible by very short ultraviolet wavelengths of light. They are visible for greater distances than non-fluorescent colors, but are not as effective when fish show a preference for the natural color of specific bait.
- Black and red can provide better contrast in both dirty water and low light conditions than can lighter non-fluorescent colors. Black, in fact, provides the best silhouette against a dark sky.
4. Choose colors that match those of foods fish feed on. Although they are called flies, dry and wet flies may also imitate minnows and crustaceans that fish feed on.
- Pink is a good color to use when fly fishing for smallmouth bass, because it is found on creek chubs, minnows, and trout, and earthworms. This color also works on trout because larger trout will eat smaller trout, including their own young. For salmon, orange, yellow, and green often work better in the spring because they match colors found in the foods those fish feed on then.
- Green chartreuse works for both fresh and saltwater fishing because of baitfish such as emerald shiners and ladyfish, while yellow chartreuse is effective because jackfish, shad, and herring all feature the color yellow.
- One small freshwater crustacean, the scud, appears brown, olive, or tan; flies in these colors work well to imitate the scud when fished in slow, slight movements. When the scud dies, it may change to a brighter color such as pink, orange, or yellow; flies in these colors may work better when fished to simulate a dying scud.
- Multi-colored flies should have the darker color on top of the lighter color, because this is the way the baitfish or insect the fly is imitating is usually colored.
Tips
- When fish are actively feeding, dark-colored flies can be more effective simply because they provide more contrast. This is particularly true of species that look up when feeding.
- Take the time to learn about the baitfish and insects found in the area you plan to go fly-fishing. These can often give you clues about what colors of flies to bring with you when fly-fishing.
- If you tie your own flies, it can be helpful to have a fly-tying kit you can take into the field to match the colors of whatever the fish happen to be feeding on now. This is called "matching the hatch." When possible, think about how the color will appear at the depth the fish are hitting at when choosing the colors you use to tie your fly.