[Reading Science] Lightning Strikes the Sea, Do All Fish Die?

The sight of lightning striking the sea.
[Photo by YouTube screenshot]

[Asia Economy Reporter Kim Jong-hwa] You may have often heard news about people being struck and killed by lightning carrying powerful electrical energy, or trees catching fire. But what happens if lightning strikes the sea? Does the powerful electricity spread throughout the entire ocean, or does it dissipate? And do the fish living near the seabed survive?

Lightning is a discharge phenomenon that occurs between clouds, or between clouds and the ground. Tiny water droplets that form clouds rise rapidly on warm air currents and collide with ice particles at high altitudes, generating electric charges. The charges formed at this time become positive charges, and the surrounding air becomes negatively charged.

Water droplets with positive charges continue to rise and move to the upper part of the cloud, while water droplets with negative charges remain at the lower part of the cloud. As the negative charges accumulate at the bottom of the cloud, a potential difference forms between the cloud's lower part and the positively charged ground.

When the potential difference between the cloud and the ground increases, a discharge phenomenon occurs as the charges suddenly flow toward the area of lower potential. This discharge, flashing with light energy, is what we see as lightning. Thunder is the sound produced by this lightning discharge.

Electricity tends to flow through paths with lower resistance. Because lightning carries very strong electrical energy and seeks paths of least resistance, its shape appears zigzagged. Lightning mainly heads toward pointed objects such as trees or tall buildings, places where negative charges are more likely to fall.

Water is a conductor of electricity. Pure water, such as distilled water, is close to an insulator and does not conduct electricity well, but tap water containing impurities conducts electricity very well. Especially seawater, which contains salts and various ions and impurities, has low resistance and high electrical conductivity. This is because the various impurities act as electrolytes.

Lightning striking the sea is a rare occurrence. As explained earlier, discharge phenomena do not easily occur over the sea. However, lightning does occasionally strike the ocean. In such cases, do all the fish near the strike point get electrocuted?

One characteristic of rapidly flowing current like lightning is that it tends to flow along the surface. In other words, the current does not flow deep into the sea. This means that the powerful electrical energy of lightning does not affect fish living underwater.

The electrical energy from lightning striking the sea surface spreads widely over the ocean, but because the energy is limited, it weakens as it spreads and eventually disappears. If you are fishing on the sea during a lightning storm, the farther you are from the strike point, the safer you are.

If a fish were to jump out of the water during a lightning strike, it would likely be killed. However, fish tend to descend to deeper waters than usual when the weather worsens, so it is safe to say that fish are not harmed by lightning. Wouldn't it be more dangerous for people to swim in the sea on a lightning day than for the fish?

This content was produced with the assistance of AI translation services.