Fishing light attractor

A Fishing light attractor is a fishing aid which uses lights attached to structure above water or suspended underwater to attract both fish and members of their food chain to specific areas in order to harvest them.

Just as fisherman seek conditions where the chance of catching fish is optimized, so fish seek areas where the chance of catching their food is optimal. Most game fish seek waters that are rich in food such as smaller fish, insects or shrimp. And, it follows, that these smaller fish, insects and shrimp congregate where their food is most concentrated.

Scientific research shows that all of this food chain has eyes sensitive to the colors of blue and green. This probably evolved because the water that these animals live in is blue to greenish in color, depending upon how much and what kind of particulate matter is suspended in the water. Pure water containing little particulate matter scatters light in the blue-purple region of the spectrum. Human eyes see this water as blue. If water is rich in nutrients and contains photosynthetic microorganisms and plants, the chlorophyll in their bodies preferentially absorb red light. The remaining, unabsorbed light is transmitted and scattered, thus giving the water a greenish appearance. If the water contains a lot of organic material from decaying plant life or suspended sediment, it may take on a yellow-brown color.

Fish and some members of their food chain have color receptors in their eyes optimized for the light of their “space”. Eyes that can see a single space color can detect changes in light intensity. This is equivalent to a world in black, white and shades of gray. In this simplest level of visual information processing, an animal can recognize that something is different in its space – i.e., that there is food or a predator “over there”. Most animals living in a lighted world have an additional visual resource: color vision. By definition, that requires that they have color receptors containing at least two different visual pigments. To efficiently perform this function in water illuminated with light, an aquatic animal would have visual pigments sensitive to the background “space” color and one or more visual pigments offset from this blue-green region, say, in the red or ultraviolet region of the spectrum. This imparts a clear advantage to these animals because they can detect not only changes in light intensity but also contrasts in color. Many fish, for example, have two color receptors, one in the blue region of the spectra (425-490 nm) and the other in the near UV (320-380 nm). Insects and shrimp, members of the fish food chain, have blue, green (530nm) and near UV receptors. In fact, some aquatic animals have up to ten different classes of visual pigment in cells of their eyes. By comparison, humans have three with maximum sensitivities in the blue (442 nm), green (543 nm) and yellow (570 nm). It is the differential responses of these receptor cells that enable color vision.

Since it has been know for a long time that a light attracts fish, shrimp and insects at night, what is the best color for this light attractor? Base on visual receptors, the light should be blue or green - the space colors of fish and members of their food chain. However, while blue or green colored light is a desirable feature it is not essential. Even if fish or members of its food chain have color receptors in their eyes centered at the blue or green spectrum, these same receptors have a broad but decreased sensitivity to other colors. Therefore, if a fishing light source is intense enough, other colors will also attract. For example, a sodium vapor light with its characteristic yellow color will attract fish - if intense enough. A fishing light attractor can also be white light because part of its total energy is in the blue to green region.

The perfect fishing light would have the following properties: 1) high intensity, 2) emit its light in a color similar to the fishes space (blue or green), 3) be powered by a portable electrical supply and 4) be submersible. The last attribute is desirable because significant amounts of light energy from land- or boat-mounted lights are lost by reflection off the surface of the water. No one commercial light satisfies all of these criteria. Many high intensity lights such as tungsten-halogen (incandescent), medium pressure mercury or metal-halide lights are so power hungry that they can only be operated for very short periods of time on a battery, thus limiting convenient portability. While green colored LEDs and low powered fluorescent lights draw less electrical energy, they are not very bright. Further, many lights cannot be submerged in water without risk of electrical shock or damage to the light system.

Fishing lights fall into two groups: those that are portable and those that are permanently mounted. Generally, portable lights are powered by batteries and this sets practical limits to the kind of light that can be used. Most portable light sources are relatively low in light intensity and have short operating times. Lights drawing more than a few tens of watts are not practical. The old classic, a 12 volt automobile incandescent headlight mounted on a Styrofoam float ring, is probably the least expensive and lasts for a few hours before the battery is discharged. Battery-operated fluorescent lamps are three times more efficient in converting electricity to light. Therefore, comparing lamps of similar brightness, they can be operated about three times longer before the battery is discharged. Also, the lifetime of fluorescent lights are about ten times longer than incandescent lights. Commercial fishing lights based on fluorescent lamps vary widely in intensity. The best use 25-40 watt lamps that emit about 1-3 thousand lumens per tube. Costing $160-$200, they are available through the internet, sport stores and catalogs. Lights made up of LED lights are an up-and-comer but to date are 10 to 100 times less bright than a fishing light using a standard 25-40 watt fluorescent lamp. LEDs are extremely efficient in converting electrical energy to light. As the cost of LEDs decrease and their brightness increases, expect to see functional fishing lights consisting of large arrays of LEDs.

Permanent lights are supplied with adequate power sources - typically, 115 volt house current. Placed on poles at the end of a dock or pier, the least expensive lights are 175 watt mercury vapor or 70 and 150 watt high pressure sodium vapor flood lights. Sold as security lights, they are readily available from most hardware or farm supply stores and cost $30 to $90. The fixture includes a photocell controller for automatic dusk-to-dawn operation and comes complete with the appropriate bulb. These lights are very bright (6-8 thousand lumens), are very efficient in converting electricity to light (operated daily for 8 hr costs $40-$100 per year), have long bulb lifetimes (24 thousand hours) and stand up to outside weather conditions. When used as a fishing light, more light can be redirected toward the water by installing a 5” X 10” piece of aluminum flashing or heavy foil bent into a half circle inside the lamp's circular acrylic lens. It should be noted that despite the excellent brightness of these lamps, a significant fraction of the light shining on the surface of the water is lost by reflection and thus will not be available to attract fish and their food chain.

These security lights can also be modified to operate submerged in water. Positioning the bulb underwater delivers approximately twice as much light to attract fish. However, the modification must be done professionally as the high voltages that power these lamps can be lethal. The power ballast and the lamp housing is mounted on a pole in a dry location. The lamp, potted in a water proof housing, is connected to the ballast via a waterproof cable. The lamp, which floats like a bobber, is held in submerged position by weights. A unique feature of this kind of submerged light is that, during daily operation, its outer glass envelope gets hot enough to prevent establishment of marine growth. This is not the case with other underwater lights which must be removed from the water after use or, if permanently submerged, cleaned frequently.

Many low cost 115 VAC outdoor flood lights use standard tungsten (incandescent)or tungsten-halogen (quartz) bulbs. Even though they are effective fish attractors, they are energy inefficient. It takes about five 100 watt tungsten lamps at an annual operating cost of $300 to deliver the light equivalent of one security lamp. Standard household fluorescent lamps are energy efficient, but low cost, weather tight fixtures utilizing fluorescent tubes are not readily available.

The best pole mounted lights for attracting fish are stadium spot lights. They are energy efficient and their superior brightness can illuminate a large area of water. Rated at 250, 400 and 1000 watts, the parabola-shaped reflector, light ballast and high intensity discharge lamp are each sold separately. A complete light fixture and lamp costs about $400. The cost of lamps with different wattage ratings are roughly the same, so most people chose the 1000 watt lamp. These lamps emit white, blue-green, green or yellow light. For most fishing waters the lamp color of choice is green. Specialty light stores also can order them. It takes two people to install these big lamps and the installation may also include a switch, timer, heavy gauge wiring and perhaps a circuit breaker, thus adding to the cost.

If possible, a fishing light attractor should be operated every night. It takes several days to a couple of weeks for fish to discover the accompanying increased concentration of bait surrounding the light. Once located, the fish return regularly.