Feeding worms with fish? Yes, contrary to popular believe it is quite OK to add fish to a worm bin. It is widely shared on the Internet that one should never add any kind of meat or fish to
a worm bin but I have done so many times and the worms seem to love to have a little seafood from time to time:-). Apart from worm composting which I have done now on a private as well as on a commercial scale for nearly 20 years now I have been involved in aqua culture too.Breeding Koi is fascinating and exciting for me but occasionally it can be heartbreaking too. Despite my best efforts dead fish are part of the hobby. During breeding season after a successful spawn with more than a hundred thousand fry that have hatched their numbers need to be reduced dramatically within a few weeks to give the best specimens the chance to grow on. Many of the smaller koi die after a few weeks, occasionally one or more adult fish die. Instead of throwing the dead animals into the garbage
container I put them into a worm bin. Within a few weeks the worms completely composted even a big fish weighing several kilograms and converted it into nutrient rich worm castings.
Feeding worms with fish
This said I have to add that there are a few things to consider when one attempts feeding worms with fish. A dead fish or some leftover seafood should only be added to a worm bin that
Tilapia half eaten by worms
Tilapia completely composted by worms after just one week
is well sealable to keep flies and rodents out. I usually use a worm bin with a strong lid that allows some air flow in and out of the bin but lets no unwanted invaders show a keen interest at the worm food inside. The fish should either be buried a few centimeter below the surface of the worm bedding or can as well just be placed on top of it. Within a few days the worms will start consuming the parts of the fish that start to decompose and will not stop until the whole animal has been converted into worm castings. I have composted dead fish in worm bins on many occasions and never had a problem with bad odors, rodent invasions or maggot infestations.
Some may argue that the resulting worm castings that are produced from the dead fish might contain pathogens and they should not be used to grow fruit and vegetables. I am not sure if food plants grown with chemical fertilizers and sprayed
with pesticides are a healthier way to produce edible plants but for those that are in doubt the resulting worm castings make still an excellent natural plant food for most ornamental plants in house and garden.