Seriola dorsalis has a 20-year culture history at Hubbs-SeaWorld Research Institute (HSWRI) in San Diego, and is now ready for commercialization. S. dorsalis is a viable aquaculture species in terms of established markets, market value, and growth rate. Here we summarize results focused on the hatchery phase of culture refinement from broodstock nutrition and spawning through larval development to fingerling production. Commercial-scale larval production runs were used to document inputs (e.g. feed, oxygen, water, and energy) and outputs (fish, metabolic byproducts) in detail to support design of a modular RAS and the associated economics of construction and operation. This project will advance the commercial-scale production and efficiency of juvenile S. dorsalis by developing techniques for year-round production of high-quality eggs and increasing the consistency in fish quality among surviving fingerlings such that more fingerlings are retained for growout.
Broodstock nutrition results demonstrated that the open-formula reference diet (OFD) produced similar egg quantity and quality when compared to a fresh fish product and commercial broodstock diet. The OFD can be used in future experimental work to determine dietary needs for S. dorsalis broodstock. We also developed protocols to spawn S. dorsalis out-of-season with no detrimental effect on egg quantity or quality. Finally, we refined larval culture protocols to improve swim bladder inflation and produce consistently high quality and quantity of fingerlings on a commercial production scale.
Our results were then used to design a modular hatchery RAS for S. dorsalis consisting of four 5,300 L self-cleaning tanks per module. An enterprise budget is being developed based on the RAS design and expected production outputs based on the research results to date. Key production parameters of the model include: 1) four 60-day production cycles per year made possible by year-round spawning; 2) average larval survival from egg to 1g fingerling of 40% (sensitivity analyses from 15-60%); and 3) quality index of 80% (i.e. where 20% need to be culled; sensitivity analyses from 70-90%). At a typical egg stocking density of 50 eggs/L, output per tank is expected to be approximately 80,000 high quality fry; per cohort = 320,000; and per year = 1,280,000. Adding additional RAS modules will increase outputs accordingly based on individual business plans.
As with many other marine fish in the USA, hatchery technologies for S. dorsalis are developed to a commercial-ready stage that awaits opportunities for growout to market on land or at sea. The growout phase will invariably have its own research needs, including ties back to the hatchery (e.g. selective breeding).