A three year study of the pearl oyster Pinctada maxima in Western Australia was carried out to provide basic biological data and to develop an understanding of the status of the stock. Aspects examined were:

1. The location of stocks within Western Australia, both geographically and by depth.
2. The population characteristics of the stocks, with emphasis on growth rates and fishing mortality rates.
3. The reproductive status, which mcluded an examination of the reproductive cycle over a large part of the range of P. maxima in Western Australia and an assessment of the genetic status of pearl oyster stocks across northern Australia.
4. The measurement of recruitment, using both spat collectors and surveys of the abundance of naturally occuring spat.
5. The further development of the fishery logbook to provide more detailed data on the operations of the fishing fleet and an understanding of fishing fleet behaviour and technology which allow a proper interpretation of catch-effort data.

The study found that the core area of stock location within Western Australia is that currently fished by the pearl oyster fishery. Some stocks of possible commercial significance were located in deeper waters (20+m depth) off the Pilbara coast. However, the stocks located in the waters off the northern Kimberiey coast were very limited and unlikely to be of commercial significance. It is likely that stocks also exist in deep water (35+m), offshore from the core Eighty Mile Beach fishing area, as this depth range was fished in the early history of the fishery. However, stocks at these depth are outside the scope of the modem fishery because of the safety requirements of the industry.