Do Goldfish Have to Have Oxygen?

Goldfish are a species of fish closely related to the carp, goldfish have been kept in captivity for many centuries on the continent of Asia, Enchanted Learning reports. To survive in water goldfish require a certain amount of dissolved oxygen to be present in their water, where oxygen is not available the fish can die from suffocation.
  1. Oxygen

    • Unlike human beings fish require a very small amount of oxygen to survive; fish require oxygen that is dissolved in water. The amount of oxygen required for fish is usually around 5 parts per million within water, with fish breathing through their gills instead of a set of lungs, according to the Fish and Wildlife Service. When held in captivity each goldfish requires around 10 gallons of water to survive with a comfortable amount of dissolved oxygen. Where the amount of dissolved oxygen falls below 5 ppm fish can become uncomfortable and in some cases result in the death of the goldfish.

    Symptoms

    • The common symptom of a goldfish that does not have enough dissolved oxygen in its aquarium or tank is the movement of the fish to the surface of the water. At the surface of the water the goldfish appear to gasp for air and attempt to increase their intake of oxygen by breathing oxygen in the air. Similar symptoms to lack of oxygen are found in fish that are affected by certain parasites and where the water pH has reached a low level.

    Causes

    • A common cause of goldfish suffocating from a lack of dissolved oxygen within the water of a tank or aquarium is the overstocking of fish within a tank, too many fish or aquatic plants within a tank or pond can result in over competition for oxygen. The death of a fish in a tank or aquarium can result in an increase of dangerous bacteria in the tank that reduces the amount of available dissolved oxygen. Too much food placed in a tank or pond for goldfish can also result in the breeding of bacteria to reduce the supply of oxygen.

    Maintenance

    • Regular maintenance of a goldfish bowl or tank can maintain a sufficient level of oxygen for goldfish survival. Adding cold water, which contains higher levels of dissolved oxygen than warm can increase dissolved oxygen levels in water with fish showing signs of oxygen deprivation. In outdoor ponds the addition of shade plants can lower the temperature of the water but increase the use of dissolved oxygen within water at night when plants take in large amounts of oxygen.