Cost–benefit analysis of two culture methods that influence pearl production from the black‐lip pearl oyster, Pinctada margaritifera

Abstract

The black‐lip pearl oyster, Pinctada margaritifera, used for round pearl production in Polynesia, is generally cultured using “ear‐hanging” where they are attached to a rope to form “chaplets.” In other countries, pearl oysters are cultured using panel (pocket) nets that are more expensive than chaplets but afford more protection to cultured oysters. Prior research has shown panel nets produce pearls of higher quality and value, potentially generating higher profits. This study used cost–benefit analysis to compare pearl production using chaplet‐based and panel net‐based culture methods. Whole farm data, including gross revenues and annual production costs, fixed and variable, were analyzed. Average production cost per pearl using panel net‐based culture was USD 22.47 and for chaplet‐based culture was USD 21.55. However, use of panel nets saved around 3,430 hr (USD 6,860) of labor a year, offsetting the greater capital investment. A chaplet‐based pearl farm generated USD 65,738 in annual profits compared to USD 88,774 for a panel net‐based farm. Positive cash flow was achieved 1 year earlier (Year 7) for the panel net‐based farm. This is the first economic analysis of different pearl culture methods for P. margaritifera and evidence of profitability will support further development of the black‐lip pearl industry in the Indo‐Pacific region.

Growth and Survival of Black-lip Pearl Oyster Pinctada margaritifera (Linnaeus, 1758) in Bamboo and Metal-framed Pocket Net Baskets Subjected to Cleaning and Without Cleaning Conditions

“…The absence of monthly cleaning, which reduced the operational cost by 82.08% (metal-framed) and 81.67% (bamboo-framed pocket net baskets), were higher than the estimates of Haws (2002), where around 40% of the total cost goes to the cleaning of biofouling itself. Some estimates, however, were much lower such as those of Johnston et al (2019), who reported 41.63% and 24.72% annual cleaning labor costs for chaplet-based and panel-net-based culture methods for P. margaritifera. In Tonga, oyster cleaning required per production cycle to operate the modeled mabé pearl farm constitute 39.18% of the total labor requirements (Johnston et al 2020).…”

“…Since 1976, the farming of P. margaritifera has been a viable industry in the tropical Pacific region (Ellis and Haws 1999;Johnston et al 2019). In 1998, the French Polynesia produced around 5 tons of pearls worth over USD 150 million.…”