If a lightning bolt strikes a lake, will it kill the fish in the lake?

When lightning strikes a lake, a powerful electric current travels through the water. This can have a number of effects on aquatic life, especially fish.

Fishing has long been a popular leisure and recreational activity, attracting not only fishing enthusiasts but also celebrities. However, for those who love the outdoors, an inevitable question is : What if lightning strikes a lake while we are there ? And for fish - creatures that spend their entire lives in the water - is this threat really that serious?

If lightning strikes a lake, are the creatures below in danger?

The skin effect is an important physical phenomenon in the field of electromagnetism, especially in high-frequency power transmission systems. Simply put, when alternating current flows through a conductor, the current tends to concentrate on the surface layer of the conductor instead of being evenly distributed throughout the cross-section.

Contrary to popular cartoon imagery, when lightning strikes a body of water, the current does not instantly kill all living things in the lake . Instead, the current travels primarily along the surface of the water rather than penetrating deep below. This phenomenon is called the “Skin Effect ,” and is similar to the way electricity travels across the surface of a car or other conductive object when struck by lightning. The current will travel across the surface rather than through the entire object.

The skin effect is the underlying principle of Faraday cages , enclosures designed to protect internal structures from electrical currents. This phenomenon also occurs in humans when struck by lightning, called "flashover," which can cause surface burns with complex shapes known as Lichtenberg figures.

A Faraday cage is a device made from a layer of electrically conductive material that is sealed and can block electromagnetic fields from entering the interior. It acts as an "electrical shield" to protect the equipment or people inside from the effects of external electric and magnetic fields.

When lightning strikes a lake or ocean, the current mainly affects organisms near the surface. However, the extent to which lightning penetrates the water can vary, and there is still much that is not understood about the exact depths to which each lightning strike can travel. So don’t count on individual fish to dive deep; they may be able to avoid being struck by lightning by swimming through a storm.

Although lightning can reach temperatures of up to 27,760 degrees Celsius (about 50,000 degrees Fahrenheit), nearly five times hotter than the surface of the Sun, water is a good heat sink, significantly reducing the temperature of lightning when it comes into contact with the water. This means that water will not start to boil when struck by lightning , contrary to what many cartoons often show.

Fish swimming near the surface or in the immediate area of ​​the lightning strike are most likely to be electrocuted and die instantly. However, fish deeper in the water are usually safer because the current is concentrated at the surface. However, if the lake is not very deep or the lightning strike is very strong, the current can still travel deep and cause harm.

While fish may be protected by the Surface Effect, humans are not so lucky. If a person is swimming or fishing on the surface of the water when lightning strikes, they could be in great danger. The electric current from lightning can travel 10 to 100 metres or more, depending on the strength of the lightning strike. This means you don’t have to be directly near the lightning strike to be affected by its energy – which can be as much as 10 million volts.

The electric current from lightning can travel 10 to 100 meters or farther.

Lightning strikes can cause a sudden increase in water temperature at the point of contact, causing thermal shock to fish and resulting in their death. The shock wave from lightning strikes can also cause damage to the internal organs of fish, especially larger fish.

To stay safe during a storm, a common rule of thumb is the “30/30 rule.” According to this rule, if you hear the accompanying thunder within 30 seconds or less after you see the first flash of lightning, the storm is close enough to be dangerous. The closer the thunder is heard, the closer the storm is. It is also recommended to wait at least 30 minutes after seeing the last flash of lightning before returning to the water.

This principle is based on the speed of sound and light . Sound travels at 343 meters per second (about 1 mile in 5 seconds), while light travels at about 300,000 kilometers per second. By counting the seconds between the flash of lightning and the clap of thunder, then dividing by three, you can estimate the distance of the storm in kilometers; divide by five to estimate the distance in miles.

Lightning strikes are not only a threat to fish but also a significant danger to humans.

Lightning strikes in a lake can have serious consequences for aquatic life, but not all fish die. The fish's ability to survive depends on many factors.

Ultimately, the best and safest way to avoid being struck by lightning while on the water is to not swim or fish when there are signs of an approaching storm. Whether you are an avid fisherman or just relaxing by the lake, safety should always come first. Lightning is not only a threat to fish, but it is also a significant danger to humans, especially when we are out in nature.