This is my first post, go easy on me!

If water is a conductor of electricity, why don’t all the fish in the ocean get electricuted when lightning strikes it?

Water, per se, is not a conductor. It’s the salts dissolved in the water that provides the conduction. The fish do not get electrocuted for the same reason birds don’t when they sit on wires: they are not grounded.

C’mon. If I’m the ocean and the lightning starts up, I’ve been learned to get my tushie out of the water ASAP.

Are you trying to tell me that if I were to float on the water (Or basically not otuch the ocean floor), I’m perfectly okay?

Or that I can stay in my pool as long as I do not touch the sides or bottom???

C’mon… Having electricity pour through me CAN’T be good. I can only assume those fishies aren’t enjoying it too much either. grounded or not.


The ocean is big and vast and the electricity dissapates. Some fish (Close to ground zero) do fall into the eternal net and meet Mrs. Paul.

Someone offer some science here, would you?

Also, I searched the board pretty thoughly… I’m surprised this has never been asked/answered before.

Hmm… Go figure.

At one time you could have asked the man who was struck by lightning more than any other and lived to tell the tale. He was a park ranger in Shennandoah National Park here in VA and was struck 4 or 5 times if I recall correctly. I say “could have” because he ended up committing suicide over a lost love. Imagine, getting zapped by lightning and surviving only to kill yourself. I hope he didn’t do it sticking his finger in an electrical outlet.

Frumpy Jones is pretty much correct. Although lightning effects through water isn’t fully understood, what more or less happens is a cone of charge travels downward until it’s dissipated into the ocean (assuming it hit the ocean- in a swimming pool, different effects are possible). Fish near the strike on the surface may be killed, but the farther away they are, the less likely they will be harmed.

AFAIK, if you were several thousand feet down at the ocean floor, you’d probably be OK, since there wouldn’t be that much electrical current left by then.

This has come up several times before, with no real definitive answer, since it really depends on local conditions, and it’s not well understood at any rate.


Frumpy said

It has.

And here:

And also here:

Fisheries Biologists commonly use electric shock to stun fish which float to the surface for counting.

If you are above water when lightning strikes, the current is liable to pass directly through you since you are a much better electrical conductor than air.
The same might hold true if you were swimming in very fresh water, but salty water is as good a conductor as flesh. In these circumstances a path through you to ground would be no better than a path through the water to ground so the current would not be concentrated on a single path, but would follow ALL possible paths in parallel.

Water is less attractive than the nearby river banks, with the exception of storms occurring out in the middle of the ocean. In this case, water just serves as another medium through which the electrical discharge travels along its way towards the ferrous body of your planet.

The question could just as fairly be asked: why aren’t birds, bugs and all manner of animals flying anywhere within the Earth’s atmosphere toasted when bolt of lightning travels through that medium? After all, the air seems to be a fairly good conductor of electricity- I mean, lightning bolts travel through it right?

The water serves more to conduct an electrical current away from waterborne objects. The ocean is also one helluva heat sink. Unless a fish is close enough to be directly roasted by the radiant heat energy of the discharge or is actually in the discharge path, it is unlikely to suffer any serious ill effects. The warnings we’re given about being near water are due to the fact that any bodies of water we are likely to be near/in (pool, pond, puddle) are small enough that a lightning strike could easily be close enough to sizzle your bacon.

What water does do is greatly decrease your body’s contact resistance, making it more likely that you will suffer injury in the event that you do become part of an eletrical circuit. A bathtub itself doesn’t make this much more likely, since most tubs are either porcelain coated or made from some kind of fiberglsss. But the conductive metal fixtures are right there in front of you, and I can imagine that the first thing some hapless person might do when startled by a submerged hair dryer would be to grab hold of the metal fixtures in a hurried attempt to exit the tub.

With a modest amount of electrically conductive water between you & the hair dryer, all you need to do to complete the circuit is grab hold of the plumbing fixtures.

I didn’t address this as directly as I wanted to.

Current does not radiate outwards in all directions like ripples on a pond. If you are only near a lightning strike but not actually close enough to have been hit by the bolt or affected by the heat, you’ll probably be OK.

Lightning hitting the surface of the ocean is just on its way towards the earth. IN order for your body to present an attractive path for the current flow, it has to be:

  1. Between the point ot entry & the point of destination (in other words, you have to be submerged so as to be “iin the way” of the bolt on its way towards the earth), and

  2. A better conductor than the water.

If you are in the path (scuba diving maybe?), but a poor conductor, you may draw some current but not as much as will flow around you in the better conductive medium.

If you are outside of the path of the bolt’s travel, you’ll not likely be harmed unless you’re close enough to sense the high level of charged particles in the vicinity of the strike. And even then it’ll probably just be a tingling sensation like eating a Peppermint Patty

I just did an internet search. I looked at a dozen “Ask the ____” sites, but could not find a definitive answer on this topic.

The basics: lightning has a lot of energy. When it hits the water, the energy is transported via the ions dissolved in the water. The energy dissipates the farther away from the strike zone.

What is not answered is how quickly it dissipates and whether it spreads conically or spherically.

The bottom line seems to be that some fish may be electrocuted, but the energy spreads out quickly which prevents it from killing every fish in the ocean.

Oh, and if lightning hit an electric eel, it would probably kill the eel, because the voltage is so much higher than that produced by the eel.

Doesn’t lightning Start at the earth, and go towards the sky, not the other way around?

I could have swore I read somewhere that the earth is negatively charged, the clouds are positively charged, and since electricity goes from negative to positive…

Or, have I stumbled upon some sort of false information?

Lightning starts in the clouds, but is met by a current emanating from the ground to complete the circuit. The electric charge from the cloud induces an opposite charge from the ground, or a tall object on the ground, and when they meet (if they do), a lightning bolt occurs.

It seems to me that the current isn’t the only problem. Ever been near a lightning strike, or hear the thunder from several miles away?

Has anybody measured the concussion effects underwater?

I think the reason people are in more danger than fish is that people are partly above the water. A quick digression on how lightning works:

During a thunderstorm, the ground and everything attached to it becomes charged. Air has basically zero conductivity, so in order for lightning to happen a column of air has to be ionized. To ionize air, you have to subject it to a large electrical potential difference. On a charged body, the gradient of the electric field surrounding it is largest where the body’s curvature is greatest–so the potential difference is greatest near the pointy parts and least near the flat parts. This means the air surrounding the pointy parts is going to ionize first, so that’s where lightning is generally going to strike.

If you’re floating in the ocean, you’re likely to be the pointiest thing around, and thus lightning is more likely to strike you than the relatively flat water. Fish obviously do not contribute to this effect at all since they’re underwater.

<<<< AFAIK, if you were several thousand feet down at the ocean floor, you’d probably be OK, since there wouldn’t be that much electrical current left by then. >>>

Let’s hope you are in some kind of underwater vehicle that can withstand the pressure at several thousand feet. THEN you may be ok; otherwise you will not be ok and will have more to worry about than a thunder storm on the surface! :wink: