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A Pearl of Hawai‘i Aquaculture

By Office of Communication Services    Published on 11/23/2015 More stories >>

oysters

After a hiatus of more than three decades, oysters are starting to be grown commercially in Hawai‘i. Global warming-induced changes such as seawater acidification have made oyster production in parts of the Mainland problematic, and so far Hawai‘i is less affected by this trend. The state’s warm and nutrient-rich waters are ideal for the bivalves, allowing them to mature faster, and the growing trend towards eating local is driving a burgeoning market for Island-grown oysters. In an acknowledgement of Hawai‘i’s native cultural methods of food production, the oysters are being grown in loko i‘a, or traditional fishponds.

Conditions, both environmental and economic, seem ideal for this new product. But things may not be so simple. Jessie Chen, a master’s student in the department of Natural Resources and Environmental Management, undertook a study of the possible costs and benefits of such an industry under advisor PingSun Leung and collaborators at UH-Hilo’s Pacific Aquaculture and Coastal Resources Center and the University of Alaska. She points out that such an analysis has never been done and is necessary due to the unique aspects of growing oysters in this Pacific island state.

Hawai‘i’s warm, nutrient-rich waters are producing delicious
oysters, more quickly than on the Mainland.

Hawai‘i’s warm, nutrient-rich waters are producing delicious oysters, more quickly than on the Mainland.

The recent creation of a long-needed water quality-monitoring program required to classify shellfish-growing areas is crucial, Ms. Chen explains. However, other food-safety considerations can raise the cost of raising oysters considerably. For example, the Hawai‘i State Department of Health may require that they undergo a 48-hour cleansing process using artificial seawater before they are sold, depending on water quality. This treatment, she discovered, which most growers will likely have to incorporate, can amount to a large percentage of a producer’s operational costs. Complex permitting processes involving restoration of the loko i‘a, and high labor costs for the necessary hand-harvesting of the shellfish are other potential hurdles.

Using data collected from a small-scale local oyster grower, Ms. Chen developed a spreadsheet model for analyzing the economic viability of such an operation. Her results showed that net return is near the break-even point and is highly dependent on the optimal levels of key variables, including oyster mortality rate and market price. But armed with this knowledge, growers now know what they have to do to succeed…and make Hawai‘i-grown oysters the sought-after commodity they deserve to be.