Does a flashlight scare fish?

Anglers have long debated whether shining a flashlight or headlamp into the water while fishing at night startles fish and ruins their chances of getting a bite. There are arguments on both sides, with some insisting that fish react strongly to unexpected light while others claim it has little effect. In this article, we’ll examine the evidence and try to determine if flashlights really scare fish away.

Table of Contents

The Case For Flashlights Scaring Fish

There are several reasons why many anglers believe that fish are frightened by flashlights:

Fish are sensitive to changes in light – Fish have excellent vision adapted to their environment. Most species can see color and rapid movements. Shining an artificial light into the water represents a sudden change that fish may interpret as a threat.
The light affects their natural behavior – Many game fish species feed at dawn, dusk or at night. Ambient light is low at these times. A bright flashlight could startle them and interrupt their normal feeding patterns.
It may reveal the angler’s location – Illuminating the water’s surface betrays the angler’s presence. Fish below are alerted that something above is casting light down. Their instinct may be to flee the area.

Flashlights create unnatural polarized light – Water polarizes light cast into it. Flashlight beams shining horizontally across the surface generate highly unnatural polarized light patterns which fish may avoid.
Fish react to shadows and silhouettes – A flashlight held above the water projects the angler’s shadow across the surface below. Wary fish could be spooked by the moving silhouette and sudden dark shapes.

For these reasons, many experienced night fishermen turn off their lights when they cast or have another person shine it from a distance away from the angler.

The Case Against Flashlights Scaring Fish

Despite the points above, there are also arguments that fish are indifferent to flashlights:

Fish lack eyelids and are always exposed to ambient light – Except for some deep sea species, most fish have eyes adapted to normal cycles of light and dark. A flashlight is unlikely to startle them.
Their wide field of vision makes light concentration irrelevant – Fish have nearly 360-degree vision. A concentrated flashlight beam represents only a small portion of what they can see.

They frequently see natural polarized light – Scattered sunlight reflecting off the water produces polarized light patterns fish are accustomed to.
Fish are more scent-driven than visual – Smell and vibrations from bait/lures trigger strikes more than what fish actually see.
Night fishermen still catch plenty of fish with flashlights on – If lights consistently scared fish away, night anglers wouldn’t continue using them.

Those arguing that lights don’t impact fish point out that other bright objects like camera flashes and boat lights don’t seem to affect fish behavior or deter them from biting either.

Scientific Research On Fish Reacting to Artificial Light

Scientific studies looking specifically at fish reactions to flashlights are limited. But researchers have examined how artificial light sources influence fish in other contexts:

A 2012 study found car headlights altered damselfish behavior – Damselfish in Hawaii took longer to emerge from shelters at night when exposed to passing LED car headlights designed to mimic vehicle traffic near coral reefs.

Salmon migration disrupted by elevated city light pollution – Research in Seattle determined that increased artificial lighting from growing urbanization interfered with salmon’s ability to use natural light cues to guide their seasonal migration.
Lab tests indicate flash photography stresses captive fish – Experiments exposing captive fish to multiple camera flashes resulted in increased ventilation rates indicative of higher stress levels.

While not directly testing reactions to flashlights, these studies suggest artificial lights can influence fish behavior. The intensity and proximity likely play a role.

Anecdotal Evidence from Anglers Using Flashlights

Looking at firsthand accounts from anglers using flashlights while fishing at night also provides insight:

Some report better luck catching fish after turning off flashlight – They say bites improve when they stop scanning lights across the water while waiting for fish to strike lures/bait.
Others say fish don’t react even to close direct illumination – They shine flashlights right on their lures while retrieving and still catch fish under the bright light.

Positioning flashlights low on the water seems to help – Keeping the beam horizontal and moving it slowly, mimicking moonlight reflections, may avoid startling fish.

Individual experiences vary, even on the same body of water. This suggests other factors may influence fish reactions beyond just the flashlight itself.

Other Considerations that May Impact Fish Responses

Several other variables beyond artificial light source likely contribute to whether fish become scared off while night fishing:

Type of species – Some fish may be more wary than others by nature even without lights present.
Water clarity – Fish in very clear water may have stronger reactions to lights than in cloudier water where illumination penetrates less.
Brightness of the flashlight – Brighter lights likely create more contrast against ambient conditions compared to dimmer ones.

Amount of human-based light pollution – Fish in isolated areas may respond more strongly than those where regular night lighting is present.
Phase of the moon – Moonlight levels change throughout the lunar cycle, making a flashlight more noticeable around new moons.
Distance/angle of the flashlight – Closer light pointed directly down likely has a greater disturbance compared to illumination from further away.

Considering these factors may help anglers use flashlights in ways that minimize impact on fish while still providing enough light to tie knots, unhook fish, change lures etc.

Tips for Minimizing Flashlight Disturbance to Fish

If avoiding startling fish with flashlights is a concern, here are some recommendations:

Use low-profile headlamps instead of handheld flashlights – Keeps hands free and light source less noticeable.

Select a flashlight with variable brightness levels – Use the dimmest setting that still allows you to see adequately.
Aim beam parallel to the water, not pointing down vertically – Mimics natural light reflection.
Angle flashlight outwards, not down towards your lure/bait – Illuminates peripherally rather than where fish are likely to strike.

Move the beam slowly and intermittently – Sweeping rapidly is more likely to alert fish.
Place a red filter over standard white light flashlights – Red light is said to be less startling for fish.
Turn off flashlight while lure/bait is in the water – Only use it briefly when needed and turn it off when cast out.

Conclusion

The debate continues among anglers on whether flashlights and other artificial light sources scare away fish at night. Research and anecdotal evidence suggest fish reactions vary by species, conditions, and the way lights are used. Reducing flashlight disturbance can be accomplished by selecting low profile, dim, intermittent lighting aimed away from the area fish are likely to strike. But many experienced night fishermen still report success even when illuminating the water directly. This indicates that with proper precautions, flashlights don’t necessarily need to keep you from enjoying successful night fishing.