A survey conducted among 40 pearl farms in French Polynesia reveals significant differences in production costs. The average production cost per pearl decreases as farm size increases.

For small farms (fewer than 25,000 oysters), the average cost of producing a pearl is twice as high as for farms holding more than 200,000 oysters. Economies of scale are most evident when farms hold between 25,000 and 100,000 oysters. Beyond this threshold, productivity gains become less pronounced.

Influence of Farming Practices

A regression analysis identified several practices that influence the rate of rejects (pearls with no commercial value):

• High oyster density on lines and larger oyster size at the time of grafting increase the percentage of rejects.
• Conversely, leaving grafted oysters in the water for a longer period and cleaning them more frequently reduces the reject rate.

Factors Influencing Selling Price

The analysis also highlights the parameters that improve the average selling price of pearls:

• Grafting larger oysters results in higher-value pearls.
• A low post-grafting mortality rate also contributes to better quality and therefore to a higher selling price.