It depends how you are fishing for them. If you're on a boat then they just get handed up to the side, unhooked and released. If you are on the bank then they are normally beached depending on the size As for eating them - yuck! The French do but then they would eat a dead person provided they were covered in garlic

Pound for pound they are one of the best fighting fish in Europe. I've caught them up to 76lb and can assure you of it! And they grow extremely fast - I was a bailiff for Leisuresport (now RMC Angling) and did a lot of the Catfish stocking in their fisheries.