Istifta 88 — Eating & drinking

Commercial fishing vessels place their huge nets [in the sea] and catch tons of fish which are then sold in the markets. It is well known that modern methods of fishing are based on catching the fish alive, and that the fishermen throw the dead fish back into the water for fear of contamination. Therefore, is it permissible for us to buy such fish in the markets of non-Muslims? Is it permissible for us to buy such fish from Muslims who are not considerate of religious laws? In both the cases to ascertain that this particular fish in front of me was taken out of the water alive, should seek the advice of an expert and reliable witness to testify to that fact which may prove difficult, impractical, and unrealistic. So, is there a solution for practicing Muslims who face difficulty in ascertaining whether or not the meat of chicken, cow or sheep is halal, and therefore take to eating fish instead?