I think everyone knows that mammals can drown when their lungs fill up with water. But this brings up an interesting point about goldfish because goldfish don’t have lungs and live underwater, so can goldfish drown?
No, goldfish cannot drown because they have gills rather than lungs. In fact, it would be very unfortunate if goldfish could drown because they can’t “breathe” oxygen unless it’s dissolved in water… that’s how the gills goldfish have operate.
However, there are ways that goldfish can “drown” underwater. This article will cover some of those ways. And yes, it isn’t technically drowning, but it is dying while underwater.
3 Ways Your Goldfish Can “Drown”
As mentioned previously, it is possible for your goldfish to drown underwater. These are not the same ways that mammals drown underwater by having their lungs fill up with water, but it’s essentially the same concept.
For reference, we will call this suffocating because drowning implies that the animal has lungs.
Not Enough Dissolved Oxygen in The Water
The first way for goldfish to suffocate is if there is not enough dissolved oxygen in the water. I will admit that this is not particularly common in nature – there is almost always enough dissolved oxygen in lakes, ponds, and streams for fish to survive.
However, it is possible your aquarium may not have enough oxygen for your fish. This is especially common if you have a tank with a small water surface area. Why?
Oxygen exchange occurs on the surface of the water. The more surface area you have, the more oxygen can cycle through the fish tank.
Do you have your goldfish in a small bowl?
Those small bowls might be cute, but they often do not provide enough oxygen for the fish to survive.
Your tank also might not have enough oxygen if you have too many plants on the surface that interfere with the oxygen exchange. Common plants that interfere with oxygen exchange include duckweed and lily pads.
To prevent this problem, I recommend having a tank that allows for more surface area and not allowing the surface of the water to become completely covered in lily pads or duckweed.
You can also pump oxygen in through a hose (with oxygen stone attached) to dissolve more oxygen into the water.
Goldfish Stops Swimming
Goldfish can only breathe when their gills have water passing over them. This means they either need to be swimming or have staying still in water that has a current.
Now, it is not common for this type of suffocation to occur in nature. Goldfish know they must move to breathe, and will always be moving a little bit to keep breathing.
The problem occurs in fish tanks. Specifically, it occurs when goldfish get stuck in a net or other obstruction for too long.
So, what is the easiest way to prevent this type of suffocation?
Don’t leave your goldfish in a net for too long and make sure there are not any obstructions that they could get stuck in inside your tank.
Fortunately, this type of suffocation is rare in an aquarium. But it is important to know that goldfish will suffocate if they are still for too long.
Damaged Gills
Finally, goldfish can damage their gills, which will prevent them from taking oxygen in through their gills.
This can happen in a fish tank if your goldfish fights with other fish, rubbing their gills against rocks, or even from an abrasive net.
Fortunately, it’s not too common for goldfish to damage their gills in a fish tank. I recommend avoiding abrasive rocks in your goldfish tank because goldfish do have sensitive gills.
Other than that, it’s doubtful a goldfish will damage its gills in a fish tank.
Final Thoughts
To answer the question, goldfish can’t drown, but they can suffocate if they stop moving, damage their gills, or if there isn’t enough dissolved oxygen in the water. The good news is that all those problems are easy to prevent.
In summary, your goldfish should not drown/suffocate in your fish tank if you take the proper steps to ensure there is enough dissolved oxygen in the water and that the goldfish can always move.