Give an account of spatial pattern of Pearl fishing and pearl culture industry around the world.
Pearls are obtained from oysters or mussels. There are a large variety of oysters that produce pearls and they are found not only in tropical waters but also in temperate seas and fresh water.
The chief pearl fisheries of the world lie in the tropical waters off the northern coast of Australia, the Asian Archipelago, Sri Lanka, the Persian Gulf (Arabian Gulf), northern Venezuela, Panama and western Mexico. India has pearl fisheries in the Gulf of Mannar along the eastern coast. Ideal conditions for pearl oysters are the hard bottoms at depths varying between 10 and 60 metres in warm clear waters of coral reef lagoons.
Japan and China have since long been engaged in pearl culture. Today pearl culture is a scientific industry.
Under pearl culture large numbers of mussels are caught in the spring season and small objects are inserted inside the shells. These small objects act at irritants to the mussels. The shells are again replanted, often in wire cages or reed baskets to keep them free from weeds and other marine growth. The mussels have a very tender body and they coat layers of pearl material over the very small objects inserted in the shells and pearls are thus formed. The cages are lifted after three to six years and the mussels are searched for pearls. It is estimated that about 60 per cent of the shells replanted yield pearls. Pearls obtained in this manner are called cultured pearls. India also produces cultured pearls along the eastern coast of Tamil Nadu and Andhra Pradesh. Tuticorin is an important pearl fishing port on the eastern coast of India.