FARMING FINNED BISON ON THE BLUE PRAIRIE: THE SWOT OF HERBIVOROUS MARINE FISH, AS EXEMPLIFIED BY KYPHOSIDAE (CHUBBS)  

Marine fin-fish aquaculture to date has almost exclusively focused on the so-called "carnivorous" species: salmon, seabass, sea bream, groupers, snappers, amberjacks and yellowtails. This has created a reliance on expensive diets high in fishmeal and fish oil (FMFO), rendering the industry triply vulnerable: to price fluctuations that accompany these commodities; to scale-up constraints; and to criticism from activist groups who believe there are better, higher uses for forage fish such as Peruvian anchovetta. Responding to these challenges, the aquaculture industry has vigorously pursued the use of plant-sourced proteins and oils as substitutes for FMFO in marine fish diets, with some encouraging successes. However, little or no effort has been directed towards the complementary corollary: identifying high-quality herbivorous marine fish that do not demand fishmeal and fish oil in their diets.

This presentation examines the Strengths, Weaknesses, Opportunities and Threats (SWOT) of herbivorous marine fish culture as an alternative or supplement to other marine species. Kyphosids (rudderfish or chubs) are traditionally highly esteemed as foodfish throughout the tropics. These fish are indiscriminate browsers, with hind-gut rumination that digests cellulose and other plant material. Our preliminary research suggests that kyphosids are amenable to hatchery culture, can grow at commercially attractive rates, and can yield excellent flesh quality when reared on formulated feeds. With species native to all of the U.S.'s prime mariculture development territories, including the Pacific Islands, Southern California, and the Gulf of Mexico, kyphosids have potential to be widely cultured, and could become foundational to the U.S.A.'s nascent marine aquaculture industry.

Two remaining unsatisfied criteria for commercial culture are: methods for successfully obtaining viable spawns from captive broodstock; and identifying nutritious, inexpensive diets that yield a high quality product. Resolving these remaining challenges should result in an economically and environmentally attractive species for mariculture that would be particularly suited to either open ocean grow-out in US waters, or in land-based RAS systems.