What can kill eels?

The simplest method of killing eels is to put them in a deep container and rouse them with salt; leave them for up to 2 hours to kill them and to remove much of the slime. They should not be completely buried in salt; a good sprinkling is sufficient. They may lose up to 5 per cent in weight during this stage.

What are electric eels predators?

Apart from being fished by humans, electric eels have no known predators. They are too dangerous for other species to go after, regardless of water levels. If the water is shallow, there's a chance that large land mammals will go after them, but this threat is often deterred with a shock.