Special report | Fishy business
Almost every morning, a blue-and-white truck pulls up to The Union Oyster House near Faneuil Hall to drop off small coolers brimming with cod fillets packed on ice. Cod is king at the country’s oldest restaurant — where more than 7,000 diners a year order what the menu describes as freshly-caught New England fish. But the cod brought to tables, and supplied by Boston-based North Coast Seafoods, is not always the local product restaurant executives say they pay for. DNA tests commissioned by the Globe showed it to be Pacific cod, which is usually much cheaper — and to many palates, less tasty.