Aquaculture 2025

March 6 - 10, 2025

New Orleans, Louisiana USA

Add To Calendar 07/03/2025 15:30:0007/03/2025 15:50:00America/ChicagoAquaculture 2025ACHIEVEMENTS AND CHALLENGES TO THE ADAPTATION OF WALLEYE Sander vitreus CULTURE TECHNIQUES TO RECIRCULATION AQUACULTURE SYSTEMSBalcony MThe World Aquaculture Societyjohnc@was.orgfalseDD/MM/YYYYanrl65yqlzh3g1q0dme13067

ACHIEVEMENTS AND CHALLENGES TO THE ADAPTATION OF WALLEYE Sander vitreus CULTURE TECHNIQUES TO RECIRCULATION AQUACULTURE SYSTEMS

J. Alan Johnson

Rathbun Fish Culture Research Facility

15053 Hatchery Place

Moravia, IA

Alan.johnson@dnr.iowa.gov

 



Iowa’s Dept of Natural Resources (IDNR) Rathbun Fish Culture Research Facility has developed pilot scale recirculation aquaculture systems (RAS) for egg incubation, larviculture, and growout to produce 225 mm fingerlings. Since 2019 over 1.1 million >40 mm fingerlings have been produced in larviculture and since 2015 over 150,000 >225 mm fingerlings have been produced in these systems. Adapting existing walleye culture techniques to RAS technology has required additional fine tuning to maintain a quality product for fisheries enhancement stocking. Larviculture techniques of clay turbidity was found compatible with biofiltration and surface spray was effective in clearing surface films to facilitate gas bladder inflation. Use of Cornell dual drain style tanks and constant water velocity had to be managed to prevent caudal fin erosion. Growth performance and survival rate from larvae to 180 days of age are acceptable however the incidence of deformity is challenging. The presence cranial deformity at rates sometimes of over 50% are a concern and studies are being conducted to elucidate the factors causing these deformities.