Is it acceptable to immerse aquatic species in carbon dioxide for euthanasia?

Immersing aquatic species in carbon dioxide for euthanasia is considered an acceptable method under certain circumstances and in alignment with established guidelines. This approach can lead to rapid loss of consciousness and death in fish and other aquatic animals. The use of carbon dioxide is specifically recognized by organizations such as the American Veterinary Medical Association (AVMA) in their Guidelines for the Euthanasia of Animals, which delineates techniques suitable for different species, including aquatic life.

The method relies on the principle that exposing aquatic species to carbon dioxide results in an increase in the partial pressure of carbon dioxide in their blood, causing respiratory acidosis, which induces sedation and ultimately, euthanasia. This technique should be performed in a controlled environment to ensure the concentration of the gas is sufficient to be both humane and effective.

It is important to note that while this method is acceptable, it must also be conducted properly to minimize stress to the animal and ensure a humane outcome. Factors such as water temperature, species-specific responses, and appropriate concentrations of carbon dioxide should all be considered to adhere to ethical standards in animal care and well-being.