The organizers of New Amsterdam Market, which resumes its weekly schedule May 1, aim to permanently preserve and repurpose the old Fulton Fish Market as a hub of food-shopping and eating. To that end, a fund-raising “Oyster Saloon” on April 9 revives a once commonly found urban institution. From 5 to 10 p.m., stalls will dispense bivalves that have been not only freshly shucked but also pickled, fried, charcoal-grilled, tucked into po’boys, ensconced in potpies, and even submerged, courtesy of April Bloomfield, into pan roasts (tickets are $50 at newamsterdammarket.com; $200 Founder’s Circle tickets include a talk by Mimi Sheraton and hors d’oeuvres).