Barstool Sports President and CEO Dave Portnoy is speaking out after an offshore windmill blade snapped and sent nonbiodegradable fiberglass shards into the water, washing up on Nantucket shores and forcing the town to close its beaches.  On Tuesday, the Nantucket harbormaster announced that six of the Massachusetts town’s beaches would be temporarily closed after pieces of fiberglass washed ashore and said anyone walking the beach should wear...