Do Goldfish Live In The Ocean? – Best Answer & Explanation

The living environment is important to goldfish species. Though you may know the goldfish live in a freshwater habitat, you still wonder if they live in the ocean as there are people who release the goldfish into the wild water. 

This article will help you answer the question “do goldfish live in the ocean” and give you a kind of scientific explanation on this topic. So, keep reading on!

Do Goldfish Live In The Ocean?

No, they do not live in the ocean and cannot survive when being in the ocean. In fact, goldfish are freshwater fish, which means the salty level (salinity) of the water must be kept under a certain number. The salinity of the seawater is too high for the goldfish to tolerate, and as a result, when exposed to the seawater, they cannot survive.

Why Can’t Goldfish Live In The Ocean?

The level of salinity is too high

The high level of salinity means the high level of ions in the water, which leads to severe dehydration for goldfish. 

The ocean is a saltwater environment with a high salt concentration, around 35 ppt salinity. This denotes that there is 35 gm of dissolved salts in every kilogram of water.

On the other hand, according to several studies, goldfish can tolerate the maximum salinity of below 20 ppt. Moreover, the goldfish are freshwater fish, which means their living water condition probably has a salinity of 0. Therefore, if they are in the seawater, they easily get dehydration – their body water flows out through their cells – and die.

The main cause of dehydration is that the ion concentration in saltwater or seawater is higher than in freshwater. Let’s take a look at the explanation below to see how this affects your goldfish body.

  • Goldfish are isotonic to freshwater. In other words, goldfish body cells have the same ion concentration as freshwater does. However, the ion concentration of saltwater is much higher than that of freshwater. As a result, the cytoplasm of goldfish cells is hypotonic to saltwater.
  • When exposed to the ocean, the goldfish osmoregulates to maintain an equilibrium of intake and output of water and salts over time. 
  • Specifically, the water from the cytoplasm enters the saltwater through the plasma membrane. This process is continuously operating once this equilibrium is reached. At that time, the cytoplasm and saltwater will have comparable ion concentrations.
  • However, regulating their bodies by simply excreting vast amounts of water is not enough for freshwater fish like goldfish. They also use their kidneys, intestines, and gills to operate their osmoregulation. All of these organs can help excrete water and ions.
  • In simple words, goldfish need less salt to maintain their body’s osmotic pressure. And saltwater contains a significantly higher salt concentration than the level they can tolerate. 
  • Accordingly, they cannot deal with such difference and get the body water of your goldfish completely driven into the seawater. Eventually, your fish are severely dehydrated, leading to death.
Goldfish cannot live in the ocean due to high salinity
Goldfish cannot live in the ocean due to high salinity


Where do goldfish live in the ocean?

Goldfish cannot live in the ocean. They are freshwater species; therefore, living in salty water like the ocean is impossible.

Can goldfish live in the wild?

Yes, they can, as long as there are freshwater environments with a variety of food sources. But the important thing is that when being released into the rivers or lakes, the goldfish will get bigger and eventually invade and destroy the ecosystem of those rivers. Thus, please don’t do that if you think of putting your goldfish into the wild.

Can goldfish survive brackish water?

Yes, they can, as long as the salinity level is below 8 ppt.

Can I add aquarium salt to my goldfish tank?

Yes, you can add a small amount of freshwater aquarium salt into the tank because this will help maintain your goldfish health.
By adding freshwater aquarium salt, you can help the goldfish reduce stress and recover faster from infections. Additionally, with the appropriate addition of freshwater aquarium salt, you can effectively prevent nitrite poisoning and unwanted diseases caused by parasites.


Goldfish probably cannot live in the ocean as the salinity exceeds their tolerance level. 

The goldfish can deal with the water having a level of salinity less than 20 ppt. The water of the ocean is 35 ppt in salinity. Therefore, they will get overhydrated and die when dumbed into seawater.

I hope this article provides you with enough helpful information on the question, “do goldfish live in the ocean?”

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