This document is the final report of research undertaken in FIRTA project 87/81 and in FIRDTF project 89/60. The results reported in the disease prevention segment (FIRTA 87/81) build upon the experience derived from six years of previous FIRTA supported investigation of pearl oyster mass mortalities. The application of preventative measures recommended by these studies and the resulting reduction in the occurrence of such mortalities has helped enable the pearl culture industry to achieve its current economic status as Australia's most lucrative aquaculture industry (the 1989 production figure is in excess of $80 million), and ranking it third in value of production after the rock lobster and prawn fisheries.

This account also reports the findings from research into methods for the on-growing of hatchery propagated pearl oyster spat. Since pilot scale quantities of spat, to facilitate this segment of the project, were not available until the summer of 1987/88 and pearl oysters take slightly longer than a year to grow to a commercially usable size/ the completion of the on-growing segment (FIRTA 87/81) was funded by a further one year grant (FIRDTF 89/60).