Ecology of pearl culture grounds

Abstract

The growth of pearl oysters either in the natural beds or in the culture farms is strongly influenced by the oceanographical conditions of the ground, the chemical substances present in the sea water, particularly some of the salt and trace elements, the quality of the plankton taken by the oysters, hydrogen-ion concentration etc. The kind and quantity of the minute amount of the chemical substances and metal ions might affect the quality of the cultured pearls (Matsui, 1958). He also pointed out that the difference in the water temperature and nutritional conditions of the grounds strongly affect the growth of the oysters, especially a conspicuous variation occurs in the thickness of the shell which in turn influence the lustre, colour, shape, degree of scratches and size and weight.