Since the first Native Americans inhabited the shores of Massachusetts Bay 12,000 years ago, people have been drawn to the bounty of this coast. European explorers were attracted to the tremendous fishing potential, and for the past 350 years Boston Harbor has served as a center for shipping and international trade. Expanding population and industrial growth had its price, however, with sewage and industrial discharges and urban runoff causing tremendous pollution problems. By the late 1970s, most of Boston Harbor was closed to shellfishing, fishing, and swimming. Beginning in the 1980s, a massive sewage treatment project, along with industrial toxics and urban runoff programs, has led to a true success story. Today, beaches are consistently safe for swimming; shellfish beds are reopened; and porpoises, seals, and striped bass are returning to their old haunts in Boston Harbor and Massachusetts Bay.