Strengthening commercial opportunities for native aquaculture products

Commodities

• Animals: shellfish
• Miscellaneous: seaweed

Practices

• Animal Production: aquaculture

Shellfish and seaweed aquaculture have proven commercial, cultural, and environmental benefits, and represent significant growth potential for aquaculture in Hawaiʻi, the USAPI and the West Coast. Seafood-loving Pacific Island residents also need healthy, local-produced food as an alternative to imported, less healthy choices and to create jobs. Although Hawaiʻi's shellfish hatcheries supply a significant amount of seed to the West Coast, local grow-out only started in 2012 when the Hawaiʻi shellfish sanitation rules were changed. Research is needed to determine which shellfish species are most suitable for the Pacific Islands, particularly in the face of climate change impacts. Farming technologies need to optimized and transferred to producers. Demand for seaweed is high with dozens of species being traditionally consumed even though the traditional source, wild stocks, are in decline. Despite the demand for seaweed, only three commercial operations exist although experimental efforts by researchers and non-profit organizations are underway. Only one native seaweed species is produced (McDermid et al. 2019).

Use of native and long-established non-native species is preferred as this helps reduce permitting difficulties, a critical obstacle to aquaculture. This work supports scaling-up production of four bivalve species; Hawaiian brooding oysters (Dendostrea sandvicensis, D. frons and Ostrea stentina) and the Eastern oyster (Crassostrea virginica). Although the latter is not endemic, it was introduced in the 1880ʻs and may be more suited to local environmental conditions and climate change impacts (Calvo et al. 1999). Refining methods to produce large shellfish seed using a FLUPSY (Floating Upwelling System) for the Hawaiian fishponds and commercial producers will assist the majority of producers lacking nurseries.

Production methods for two seaweed species (Halymenia hawaiiana and Codium edule) will be refined in order to diversify production for existing producers and to ease entry into commercial production. High demand coupled with diminished wild stocks are spurring interest in seaweed aquaculture. Increased interest is also motivated by the recognition of seaweed's cultural significance. Although some businesses and community groups are now growing seaweed in small quantities with a variety of difficulties, more research and development is needed to expedite increased, reliable production. The two species chosen for emphasis are the furthest along the development spectrum and are the most likely to be immediately adopted by producers. To overcome the limited shelf-life of most local species, post-harvest methods will be developed to extend shelf life. Value-added products will be developed and tested, including dried seasoning mixtures and sauces. Consumer acceptance will be assessed and estimates of willingness-to-pay derived. This work will benefit at least five shellfish growers, four hatcheries, three seaweed producers, cultural practitioners, seafood distributors and numerous prospective producers. The findings and new technologies will establish a pathway for producers to add these species groups to their existing production.

The overall goal of this work is to increase and diversify aquaculture production using low cost, low input aquatic species that do not require feed, have lower permitting requirements and provide environmental and cultural benefits. The Pacific Aquaculture and Coastal Resources Center (PACRC) at the University of Hawaiʻi Hilo (UHH) will work directly with producers and supporting entities to foster commercialization and production expansion of shellfish and seaweed. Despite high demand and intense interest in Hawaiʻi and the U.S. Affiliated Pacific Islands (USAPI), bivalve and seaweed aquaculture requires further research and on-farm development to increase production and develop marketing opportunities. This initiative will focus on further refinement and transfer of recent developed aquaculture methods for native bivalve and seaweed species.

For example, to meet the needs of new shellfish producers that lack nursery systems, production of larger shellfish seed is needed. As another example, new seaweed producers require a supply of seaweed "starts" since not everyone has access to wild material and some species have become rare in the wild. Marketing research and development of new value-added products will extend shelf life and increase economic returns to the producers. Additionally, these species groups have cultural significance and will contribute to the broader effort to restore functionality to the traditional Hawaiian fishponds (loko iʻa).  It is estimated that the loko iʻa produced over 2 million pounds of food annually prior to colonization (Costa-Pierce 1987). Despite tremendous challenges, these ponds are being restored and put into production. Shellfish and seaweed are particularly appropriate for these systems. This work will directly involve all of the existing major producers and will identify and assist the most likely new adopters.

The PACRC is an university-based aquaculture research, training and educational center, the only one of its kind in Hawaiʻi. It has infrastructure to support all major aquaculture species groups (marine fish, shellfish, freshwater fish, seaweed).  Aside from providing the training grounds for the only four year academic aquaculture program in the region, it is publicly accessible to a wide range of trainees and producers. Currently the PACRC is teamed with the Hilo Aquaculture Cooperative to co-manage the Hilo Bay Aquaculture Demonstration site, a small “farm” for testing shellfish and seaweed. Both the Cooperative and the “farm” are the first of their type in Hawaiʻi.  The PACRC also hosts a state- and region-wide extension program to provide technical assistance to producers, loko i’a and other institutions.

The following objectives were designed as priority actions needed to move aquaculture production forward in the Pacific Island region, while also providing benefits to some West Coast stakeholders.

Objective 1. Scale-up production of the Hawaiian brooding oyster species (Dendostrea sandvichensis, Dendostrea frons and Ostrea stentina) at the PACRC and four producer sites (Kauai Sea Farm, Hilo Bay, Kualoa Ranch, Paepae o Heʻeia).  Marketing research will be conducted on three islands (Hawaiʻi, Oʻahu and Kauai) for these species. D. sandvichensis was first developed for aquaculture ten years ago and has since been selectively bred for enhanced growth rate and pink shell color. It has been successfully cultured at nine sites around the Hawaiian Islands, primarily for regenerative aquaculture projects. A second Hawaiian oyster species, Dendostrea frons, was recently identified at the Nomilo (traditional Hawaiian fishpond), the growout site used by Kauai Sea Farms as this company experimented with the first commercialization of a native oyster species. Ostrea stentina was documented for the first time in Hawaiʻi in 2018 (Sutton et al. 2018).  Although the brooding oysters tend to be smaller than the cupped oysters, this is an advantage in the current market as most consumers prefer smaller oysters as raw, half-shell product. This objective aims to take steps to commercialize these species and assess market potential.

Objective 2. Develop the Eastern oyster (Crassostrea virginica) as an alternative to the Pacific oyster. Efforts to "rescue" the Eastern oyster stocks from Pearl Harbor to serve as broodstock for hatchery propagation are currently underway. The Eastern oyster may be a better species due to its tolerance of low salinity and high temperature, both of which are typical of the loko i'a (traditional Hawaiian fishponds) and other prime growing sites. It may also be more resistant to climate change impacts and the ubiquitous pest, mud worms (Polydora spp.).  These worms burrow into the shell, weakening it and making the product unsaleable.  The PACRC will work with three producers to assess the performance of C. virginica in Hawaiian fishponds and a shrimp farm to evaluate the aquaculture potential as compared to the Pacific oyster (Crassostrea gigas).

Objective 3. Scale-up the production of large oyster spat for the Hawaiian, Eastern and Pacific oysters using the newly re-built solar-powered FLUPSY (Floating Upwelling System) at the Heʻeia fishpond (O'ahu). Hawaiʻi's newer shellfish producers and many West Coast farms require large seed (>5mm) which is difficult for hatcheries to produce since microalgae requirements are high. FLUPSYs are designed to rear seed by taking advantage of waters with high natural productivity. Data on growth and survival rates for Pacific oyster seed is currently being collected in small-scale trials in the FLUPSY. This basic information will guide scaling-up of semi-commercial quantities of large seed for several species for the benefit of the nursery operators and the recipient farmers.

Objective 4: Scale-up production of two native seaweed species (Halymenia hawaiiana, Codium edule) using land-based systems at the PACRC and partner sites with the goal of producing at least 500 pounds of each species per month. The effects of fertilization, shading, harvesting frequency and water flow will be tested to determine the effect on growth rate. Both species were chosen for their relative ease of cultivation and demand as fresh product. Both have potential for medical uses or for secondary, commercially valuable products such as phycobilins.

Objective 5: Develop value-added products and conduct test marketing for the two species in Objective 4. Methods of extending the shelf-life of fresh product and drying protocols will be tested. At least three value-added products (a dry poke mix, tsukudani and furikake) will be developed. The popularity of poke (chopped raw fish with seaweed) suggests these products would be the most immediately marketable. Taste-testing and marketing surveys will be conducted with consumers, chefs and seafood buyers.