Impact of Starter Microdiets for Raising Saugeye (Hybrid Walleye) Fry for Great Lakes Aquaculture
Funded by- Wisconsin Sea Grant
Background: The Midwest consumes over 1 billion pounds of seafood products per year but less than 4% comes from aquaculture operations in the region. Walleye are one of the most valued food fish in Wisconsin but most are imported from Canada and caught from wild sources. Studies conducted over the last decade have shown that, compared to purebred walleye, the walleye hybrid (saugeye) grows significantly faster, is more tolerant of typical aquaculture conditions, and has virtually identical processing and organoleptic properties making them ideal for commercial food fish aquaculture in water reuse systems. UWSP NADF has experienced substantial success over the past seven years raising saugeye. By using hybridization, enhanced husbandry, and indoor closed-loop production we have been able to assemble systematic culture protocol that has advanced walleye food fish production to the point that a Wisconsin commercial walleye industry is emerging. There remains a limited number of bottlenecks for commercial saugeye industry production in Wisconsin, with one of the most important being fry (larval) growth and survival.
Importance: Enhanced production of high quality fry and fingerlings reared intensively on commercial feed is a key target for successful expansion of the Wisconsin aquaculture industry. Despite saugeye fry being produced - survival rates are often highly variable and growth potential has not been fully realized. Also, quality problems such as skeletal and developmental deformities are often present. At least part of these issues may derive from sub-optimal nutrition. A critical phase in fry production is the early stage of exogenous feeding, where fry digestive capabilities are limited and, traditionally, only live feeds have been used. However, live feeds are expensive and difficult to manage. Therefore, few culturists are willing to apply them to commercial saugeye larviculture. For successful commercial intensive production of saugeye as a food fish, the future lies in commercially produced, dry, starter microdiets.
Project Goal: To investigate emerging species suitable for commercial food fish aquaculture in the Great Lakes region and to identify a species-specific diet that will be beneficial to commercial saugeye fry production that meets growth, survival, and developmental needs. Specific objectives are to: 1) Compare five commercially available starter microdiets for the production of saugeye fry in larviculture systems to achieve optimal growth, survival, and developmental milestones, and 2) Investigate the benefits of starter microdiets on saugeye fry raised at commercial densities with specific emphasis on growth, survival, and development, and 3) Production and economic reports will be created to compare the constraints and costs of using these newer microdiets in saugeye fry production while demonstrating and transferring information to the Great Lakes region's private aquaculture industry through various outreach activities.
Photos: Intensively reared and feed trained saugeye fry 15 days post hatch (at left) reared at UWSP NADF in larval rearing system (at right).