The McDonald's Filet-O-Fish was originally made from halibut, a more expensive seafood fish, in the 1960s. The sandwich was created by a McDonald's franchise owner in Cincinnati, who needed a meatless option for his predominantly Catholic neighborhood where many people traditionally didn't eat meat on Fridays. The original version was created with a special batter and tartar sauce, but founder Ray Kroc had already developed a meat-less alternative, the Hula Burger. The company switched its fish to Alaskan pollock in 2013, which aligns the product with sustainable fishing practices certified by the Marine Stewardship Council.