World Aquaculture December 2019

22 DECEMBER 2019 • WORLD AQUACULTURE • WWW.WA S.ORG flavescens (Fig. 12), a valuable coral reef fish in high demand for the aquarium trade (Callan 2016). Off the Kona coast, more than 280,000 yellow tang are collected annually from the coral reefs and OI’s achievement in producing captive-reared fish could eventually provide aquarium hobbyists with an alternative to wild-caught fish. The PACRC has a program to conduct research on the breeding and basic biology of coral reef species, including potters angel Centropyge potteri , flame wrasse Cirrhilabrus jordani , tinkers butterfly Chaetodon tinkeri , as well as two species which are also foodfish species, peacock razorfish (Nabeta) Iniistius pavo and Achilles tang Acanthurus achilles . Further development of marine fish is inhibited by the lack of public and private funding for existing hatcheries and the degree of investment required for commercial-scale marine fish culture. It is also challenging to obtain permits for direct seawater intake as much of Hawaiʻi’s coastline is the most regulated part of the State. Many facilities such as OI, the PACRC and Anuenue Fisheries Resource Center depend on seawater wells. Despite the additional cost of drilling wells, an advantage is the increased level of biosecurity and the ability to obtain cold and warmwaters. For example, a fish farm was operated using heated water from the Puna Geothermal Plant, which provided approximately 25 percent of the electrical needs of Hawaiʻi Island. Tilapias are the main freshwater species cultured in Hawaiʻi today, along with Chinese catfish Clarius fuscus . Over thirty years of regulatory prohibition on the importation of new tilapia stocks hampered the ability of tilapia farmers to obtain new strains, leading to inbreeding and less efficient production. Recent easing of this ban has created new opportunities for tilapia producers. There are at least two major tilapia producers, one on Oʻahu (Hawaiian Fish Company) (Fig. 13) and one at the Kohala District of Hawaiʻi Island (Kohala Mountain Fish), as well as several large aquaponics operations that grow tilapia. One of the more unique forms of aquaponics is Kulahaven Farms, which grows watercress and rainbow trout using the cooler water available at higher altitudes (Fig. 14). Marine Shrimp and Freshwater Prawns OI’s Shrimp Department has an international reputation for research on the selective breeding of Pacific white shrimp Litopenaeus vannamei . In 1990, OI partnered with the University of Arizona to develop the world’s first captive population of specific pathogen free (SPF) L. vannamei and OI was the first organization in the world to develop a family-based breeding program for this species. As a member of the USDA-funded Marine Shrimp Farming Program from 1985 to 2011, OI transferred selectively-bred SPF shrimp to the private sector to promote a shrimp broodstock industry in Hawaiʻi. Hawaiʻi is now home to six commercial SPF broodstock suppliers. Shrimp exports (largely SPF broodstock) generated an estimated $24 million in export revenue in 2018 (United States Census Bureau 2019). Two of the largest SPF shrimp broodstock companies have been operating out of HOST Park (Shrimp Improvement Systems Hawaii LLC and Moana Technologies LLC) for over a decade. Sunrise Capital, Inc. operates a 44-acre shrimp farm on Kauai that produces SPF/SPR shrimp broodstock and also sells for consumption. This company also cultures hard clams and Pacific oysters. Shrimp grow-out has continued, largely located on the North Shore of Oʻahu, but land prices and regulations constrain further development of shrimp farming for the purpose of consumption. Among other early accomplishments, researchers at the AFRC developed culture methods for Malaysian prawns Macrobrachium rosenbergii that supported development of 20 commercial prawn farms by 1982 (Ogata 1982). Production peaked in 1983 with 373 t valued at $3.3 million from 22 farms with about 281 ha of pond area. Due to relatively low yields for the production effort, the industry has since declined to just six farms in 1999, producing only about 18 t (Fast and Leung 2003). Although no official statistics are available since then, commercial prawn production is believed to be quite small, supplying a local niche market, but the opportunity exists for expansion of this activity. FIGURE 12. Captive-bred yellow tang (Zebrasoma flavescens) . OI scientists recently closed the life cycle on this important coral reef fish and now have sexually mature, F2 generation adults. Photo: Chatham Callan, OI. FIGURE 13. Ron and Lita Weidenbach of the Hawaiʻi Fish Company, the oldest land-based commercial fish farm in Hawaiʻi. Ron has also served as the President of the Hawaiʻi Aquaculture and Aquaponics Association (HAAA) for many years. Photo: Ron Weidenbach.