In a massive multi-story shopping mall, customers jostle for space amid endless glass display cabinets that sparkle under bright lights. The place buzzes with excitement as shoppers look at bracelets, rings, necklaces and other intricately crafted treasures.

Welcome to Shuibei in Shenzhen, a former fishing village in southern China that has become the epicenter of the nation’s marine pollution. insatiable appetite for goldand a street-level barometer of the economic and market forces affecting demand. More than 10,000 businesses are clustered in various city blocks, a maze of wealth that ranks among the world’s largest gold retail markets.