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Can Fish Drown?

Author : Efrain Silva

“Daddy, you know how fishies can swim around forever in the tank or ocean, but people drown and lose air after only a couple of minutes? Why is that? Why can’t people swim forever in the water and be happy & free?”

Perhaps one of the most pressing questions a child may have (I know I certainly did, back in the day) is whether or not fish can drown. People can drown. So why can’t fish? This tends to be a child’s natural, perfectly normal thought pattern. But we have to remember that fish are not made the same way that we are….they can breathe underwater….but can they drown in any way?

Good question it is. And some people, believe me, still ask it, even adults. It’s a perfectly valid one to ask.

Understand this, first and foremost : Water, by its very nature, tends to hold dissolved oxygen within it. And fish, just as God made them, are actually really good at extracting such oxygen ; that is why they can continue to breathe while under the water, whereas we, as frail human beings, eventually run out of air and drown / choke to death. You could say that, just because of this one fact alone, that it is a literal impossibility for a fish to drown (at least while under the water). Fish, of course, can run out of air when above water, but that’s a whole ‘nother issue.

A fish can, on the other hand, die while under water for lack of dissolved oxygen, losing breath and choking out. That happens when there fails to be enough dissolved oxygen for them to extract, faster than at the rate in which they lose such oxygen. This can happen, for instance, when there is a massive fire underwater that kills such oxygen and life thereby (fire is a huge oxygen killer ; though, ironically, a basic fire can die out when there is not enough oxygen, at the same time).

Large blooms of algae, as a side note, are another thing that can cause any water’s oxygen levels to diminish, especially if it’s present in large amounts in a closed river, for instance. Also remember that a fish’s gills simply can not process air. It’s not made to do so.

Human lungs need air, which is found only above water. And fish gills need moisture, which is found mostly under the water. That is why, when either of our species lacks what it needs, it loses breath and ‘drowns’ or chokes to death. It’s really as simple as that. So to answer the question, in a nutshell, fish can’t ‘drown’ when under water, like humans can, not even if one of more of their gills happens to be injured / not working properly.

Check out our other similar blogs here, by the way, and leave a comment! Thanks so much for reading. Stay safe out there.