Can Fish Drown? Do You Have Enough Oxygenated Water

What’s going on in your aquarium? Are fish at the very top of the tank do they look like they are gasping for air? Yep fish need air well no they need oxygen and there’s oxygen in water too just not as much. 

There are 210,000 parts per million of Oxygen in the air which equates to around 21 percent oxygen. What about water though well that’s only 8 parts per million of Oxygen in water which equates to under 0.1 percent.

Fish need around 4 parts per million to function healthily. This is half of what’s generally in water making fish both very adept in fact amazing at getting oxygen out of water. As well as always being at risk of drowning. 

It’s a good job their gills are so good and these stats put things into some perspective. We need to be ready to up the oxygen and keep our fish healthy.

Can Fish Drown

Fish can drown or suffocate if the level of dissolved oxygen is too Low in their waters or if they are out of water for too long and are unable to get oxygen via their gills.

This is only the tip of the iceberg let’s dive deeper and investigate how this all works. Fish drown or suffocate because they can no longer get enough dissolved oxygen out of the water. This could be for a number of reasons.

Too Many Fish

Keeping too many fish together in too small of a tank can cause fish to drown. This is because overstocking your fish tank with too many fish causes much more co2 ( carbon dioxide.) When fish breathe out they breathe out carbon dioxide the same as us. Too many fish means much more co2 and less dissolved oxygen.

Fish Waste

Lots of fish waste or fish poop will cause excess nitrogen, This is because bacteria will break down the waste which uses up precious oxygen. This oxygen may be needed for our fish and if they don’t get enough oxygen yep they could drown.

Then there’s ammonia if a spike happens it will cause dissolved oxygen and the possibility of drowning our fish. This happens when ammonia is oxidized in water as nitrification happens oxygen is consumed and depleted.

Nitrogen And Algae 

With excess nitrogen in the water, we also have the likelihood of algae forming and breeding. This along with algae dying uses copious amounts of oxygen. Excess nitrogen fuels the growth of algae once the algae start to die they sink and decompose this process uses so much oxygen. This can cause our fish to drown too.

Some Chemicals

When using water conditioners and or some medications to help prevent diseases. Or the symptoms of diseases please read carefully the guidelines and the instructions. As sometimes they do affect the dissolved oxygenation of the water. It’s always best to agitate the water to get some movement and add more oxygen into the water when using these additives.

Plants

I know this is a strange one how would plants cause fish a drowning situation? Here me out plants create oxygen when the lights are on daytime. Around 8 hours a day at night they breathe oxygen so be careful they are depleting oxygen and leaving co2 carbon dioxide behind.

Salinity

Using salt will have an effect on the bioavailability of dissolved oxygen. Even freshwater tanks can have trace salts as we hobbyists sometimes treat fungal and parasites with Epson salt for instance. Occasionally a fish may have a salt bath just be vigilant about oxygen levels.

Temperature

Of course, temperature and water parameters are going to play a role in oxygenation. The warmer you keep the water the less oxygen you will have available for your fish. Just bare this in mind when deciding what fish to keep and other tankmates.

The Process Of A Drowning Fish

How The Gills Recieve Oxygen

Now we know fish ned and breathe dissolved oxygen basically oxygen from water. We know what can consume our aquarium’s oxygen we also know this can drown our fish but how.

Let me explain when a fish takes in water over its gills they open their mouths. This allows water to pass over the gills as the mouth opens it pushes the gills making them wider and allowing the tissue and vessels to receive water. These vessels then take the oxygen out of the water.

As soon as this happens the fish closes its mouth pulling the gills the other way and allowing the water to leave via the back of the gill. This water has no oxygen in it as the fish has already taken this and the vessels have pumped it into the bloodstream.

More Oxygen

This means that the fish needs more oxygen coming into the bloodstream than was already there. If not we have a problem the fish will start gasping looking for air. Well, oxygen but you get the drift Now fish don’t have lungs and drowning is the filling of lungs with liquid. I’d say those gills are the fish’s lungs and they passed a liquid (water) over them and into the bloodstream and now they can’t breathe.

You can look at this any way you like suffocating asphyxiation yada yada the fish drowned to death it’s that simple.

Fish Out Of Water

Just so we are sure what happens to a fish out of water. Once the gills have dried up and no more water is passing over them. The fish can no longer breathe there’s no oxygen as the fish can only get oxygen from water, not from the air.

The fish is going to drown. There’s liquid in the system water but it’s now co2 carbon dioxide. The fish has no more oxygen it’s not choking or being strangled id say it’s drowning. Suffocating to me would suggest the airways were blocked similar to choking. 

Cambridge dictionary drown. And the word drowning ill let you have a look and decide looks pretty clear to me.

Yes Fish Can Drown Conclusion

Well, I for one hope you had a good read and enjoyed it. I also hope you agree yes fish can drown If they have low oxygen in their bloodstream they can no longer breathe. This is the definition of drowning.

We as hobbyists need to make sure enough oxygen is in our tank’s water. A simple test kit can do this we can agitate the water and put an air bubbler or airstone in to help. All joking aside it doesn’t matter if we say suffocation asphyxiation or drowning what matters is healthy fish.

Please feel free to look around the site and remember fish can drown.