sufficiently mature to fend for themselves were they released back into the wild. These days this method is practiced by fisheries throughout the world. Before the Spanish came, the Filipinos also only used large mesh nets when fishing in rivers, lakes or in the sea. This ecologically sound practice protected the young ensuring future good catches. However, the competition brought by the Spaniards resulted in the use of such small mesh nets that the Spanish themselves eventually had to regulate the nets to prevent the destruction of the fisheries. Other Pre-Spanish Filipino industries included the manufacture of liquors and vinegars like tuba, basi, etc., the production of hides for export to Japan, export of edible bird's nests from Northern Palawan to China, the raising and trade of civet cats, the manufacture of gunpowder, the making of wax for export to China, and the making of cotton stockings for export. Spanish era The Japanese population in the Philippines has since included descendants of Japanese Catholics and other Japanese Christians who fled from the religious persecution imposed by the Tokugawa shogunate during the Edo period and settled during the colonial period from the 17th century until the 19th century. A statue of daimyō Ukon Takayama, who was exiled to the Philippines in 1614 because he refused to disavow his Christian beliefs, stands a patch of land across the road from the Post Office building in the Paco, Manila. In the 17th century, the Spaniards referred to the Paco Area as the 'Yellow Plaza' because of the more than 3,000 Japanese who resided there. In the 16th and 17th centuries, thousands of Japanese people traders also migrated to the Philippines and assimilated into the local population. pp. 52–3 Many of the Japanese men intermarried with Filipino women (including those of mixed or unmixed Chinese and Spanish descent), thus forming the new Japanese mestizo community. A sizeable population settled in Manila, Davao, the Visayas and in the 1600s in Dilao, Paco, and Ilocos Norte Province. This hybrid group tend to be re-assimilated either into the Filipino or the Japanese communities, and thus no accurate denominations could be established, though their estimates range from 100,000 to 200,000. Many were killed or expelled after World War II because of their alleged collaboration with the Japanese Imperial Army (mostly as translator). Many Japanese mestizos tended to deny their Japanese heritage and changed their family names in order