Rise and Fall of Freshwater Prawn (Macrobrachium rosenbergii) Culture in Hawaii: 1965–1999

Abstract

Following Shao-Wen Ling's discovery of larval-rearing requirements for the freshwater prawn Macrobrachium rosenbergii in Malaysia during 1961, Takuji Fujimura developed mass culture technology for the species during the late 1960s. These technological breakthroughs resulted in widespread interest in commercial culture of prawns in many places, including Hawaii. The state of Hawaii actively supported freshwater prawn aquaculaire in many ways. The first commercial production of freshwater prawn in Hawaii began during 1972 and was based on traditional pond culture techniques developed in Hawaii. Those techniques included routine stocking of ponds with prawn seed and harvesting (culling) larger prawns at least monthly. Ponds often were not drained for many years, and only then for maintenance. Freshwater prawn production reached a maximum of 372,700 kg/yr in 1983 valued at $3.3 million, but then collapsed to 47,600 kg/yr in 1987. Prawn prices during that period steadily increased from $7.70 to $l4.17/kg. Production revived briefly in 1991–1992 after prawn prices reached $17.71/kg in 1990, but prices collapsed to $9.79/kg in 1992 and production then fell to 40,200 kg/yr during 1993. Production remained low thereafter and was only 18,300 kg/yr during 1999. We discuss those factors that were most likely responsible for the ultimate collapse of the freshwater prawn culture industry in Hawaii. These factors include biological and physical-chemical conditions that resulted in low yields. The industry was founded on the assumption that pond yields would be 3000–4000 kg/ha/yr, but yields were generally 1000–1700 kg/ha/yr. Those lower yields resulted in high production costs per kg, and made cukured freshwater prawns noncompetitive in the marketplace with imported freshwater prawns and marine shrimp. Unsuccessful marketing attempts with Hawaii farmed prawns and lack of a clear market position for freshwater prawns also contributed to production declines. Many of these same problems still persist, and it is unlikely that freshwater prawn production will do more than fill a small niche market in Hawaii.