For centuries, the main sources of wealth were pearling, fishing, and trade. At one time, Qataris owned nearly one-third of the Persian Gulf fishing fleet. With the Great Depression and the introduction of Japan's cultured-pearl industry, pearling in Qatar declined drastically. | For centuries, the main sources of wealth were pearling, fishing, and trade. At one time, Qataris owned nearly one-third of the Persian Gulf fishing fleet. With the Great Depression and the introduction of Japan's cultured-pearl industry, pearling in Qatar declined drastically. |