Re: What is the Most Humane Way to Euthanize a Fish?
#57
Nathan Hill wrote an excellent detailed article on the pros and cons of the various methods used to euthanize fish. Reading through that again after seeing this thread I would urge anyone who needs to do this (and we all face it sooner or later) to keep either a bottle of Aquased (2-phenoxyethanol) or a bottle of clove oil in the fish first aid kit.
Many of the commonly recommended methods are NOT a pleasant way for the fish to die and particularly in unskilled hands. You can read the original article in full on the PFK web site
here, but below are just a few reasons why some of these methods are not the best option:
Ice - can be used for very small fish (up to 5cm but must be done correctly. Fish are cooled in water with crushed ice added, but this must be done slowly enough to prevent ice crystals from forming in the fish's body before death which would be extremely painful. The ice must not come into contact with the fish and fish should never be placed directly into a freezer (as some recommend).
CO2 overdose/Alka-Seltzer - This is very unpleasant for the fish, so much so that it has been banned as a method of slaughter for commercial food fish production in the EU. Should not be used.
Boiling - this shouldn't need explaining, but as this one does the rounds still, it should never be used. Death is slow and extremely painful.
Hitting the head - can be quick and painless, but only if you are confident enough and capable enough to succeed with the very first blow. Also consider that once the fish is out of water you need to act immediately to prevent stress from that situation. If you're squeamish, nervous or at all unsure, don't attempt this.
Decapitation - Must be achieved with one clean cut and immediately followed by pithing: insertion of a sharp object into the brain cavity to destroy the brain. If this isn't done the fish can remain conscious for some time after decapitation.
Flushing - extremely unpleasant for the fish. It will be subjected to the trauma of being netted, then a sudden and extreme change of water parameters and temperature. Many fish will still be alive when they hit the sewage system and then die in human sewage. Some even survive and end up in the waterways which is why it's also legally a questionable practice.
Other methods are also covered in the PFK article, but suffice it to say for the majority of us an anaesthetic overdose is the least traumatic and most peaceful way to say goodbye to a fishy friend.