Ruling 2634 — Slaughtering and Hunting Animals

It is not necessary for a fisherman to be a Muslim [for the fish to be lawful to eat], nor does he have to mention the name of Allah the Exalted at the time of catching the fish. However, a Muslim must witness – or attain confidence (iṭmiʾnān) in some other way – that the fish was caught alive in the water or that it died in the net in the water.