Q:
a) What is the rule on scaled fish which dies inside fishing nets?
b) Is it allowed to buy/sell inedible water animals? Can we sell them to people who consider eating them as ḥalāl? Is it permissible to trade in them for purposes other than human consumption such as bird and animal feed or manufacturing?

A:
a) Scaled fish which dies inside fishing nets of a fisherman is ḥalāl.
b) It is not permissible to sell or buy any of the types, which are not sanctioned for human consumption, even if the buyer is among those who consider it ḥalāl to eat. However, if they serve some rational, ḥalāl, and beneficial purposes other than food, like in medicine, manufacturing, and feeding birds/animals, there is no problem in doing business in them for the said purposes.