Production of Walleye (Sander vitreus) and Hybrid Walleye (S. vitreus x S. canadense) with Formulated Feed Utilizing Various Rearing Systems and Novel Technologies for Commercial Food Production Gregory Fischer, Facility Operations Manager University of Wisconsin-Stevens Point Northern Aquaculture Demonstration Facility
Objectives The UWSP-Northern Aquaculture Demonstration Facility (Bayfield, WI) has been conducting research for > 10 years to evaluate and demonstrate commercially available new technologies for producing purebred and hybrid walleye for stocking and food fish. The project consisted of different areas including: Intensive production and seasonal advancement of captive walleye and sauger broodstock. Intensive production of fry utilizing only commercial processed feed. Production of walleye and hybrids to food market size(>454g)(1.0 pd) using intensive rearing and recirculation systems with formulated feed.
Sander vitreum Sander canadense Female Walleye X Male Sauger Hybrid Walleye (Saugeye)
Why Walleye and Hybrids??? Walleye have many characteristics suitable for aquaculture production: Ability to rear and spawn broodstock intensively and out of season. Ability to do entire rearing cycle intensively on commercial feeds. High growth rates and good feed conversions. Existing markets and good prices ($12-18 lb). Good potential for aquaponics.
Egg Collection
Incubation
240 L (60 gal) round tanks Sidewalls painted black Gray bottom Adjustable lighting Directional flow-thru 20ºC(70ºF) water (2-8 lpm) Clay(old mine #4)(50-80 NTU) 24 hr feeders Surface spray Removable screens Daily cleaning system Experimental Tank Setup for Phase I-II Intensive Rearing
Water inflow pipe Feeder Surface spray Directional water flow Center screen
Otohime fry feed 200-1400 m Nelson Silvercup walleye grower 1.0mm
Captive Broodstock Winter period Photoperiod/ Temperature Manipulation
Seasonal Advancement of Spawning Hormone Injection Method Manipulate water temperature Human Chorionic Gonadotropin (hcg)hormone 2 injections: 3-5 days apart Females 500 IU/Kg Males 350 IU/Kg
Out of Season Spawning Photoperiod and Water Temperature Manipulation Manipulate Water Temperature and Photoperiod Overhead Lighting, Water Chiller and Boiler Start August- set eggs- Early winter spawn(feb) Extend spawn into June
Cold Banking Water Temperature Manipulation Utilize intensively reared fingerlings >20.0 gms Manipulate Water Temperature to provide winter Provide cold 8ºC water Successfully coldbanked for 4 months with little mortality Move fingerlings into heated RAS for growout Able to provide multiple stocking events from one cohort
Cold Banking Water Temperature Manipulation >20.0 gms start WWRAS: 23 C Ave Length: 304.23 mm Ave Weight: 264.67 g CWFT 90 Days Ave Length: 167.44 mm Ave Weight: 47.56 g CWFT 129 Days Ave Length: 143.12 mm Ave Weight: 28.36 g
Materials and Methods Recycle System Used For Phase III-IV Intensive Growout RAS Parameters: 53,000 L water capacity 33 m³ tank culture space Fluidized sand biofilter Drum Filter Dual drain circular tanks Oxygen cone In sump electric heater 23ºC (74ºF)Water temp.
366 346 317 288 262 251 228 222 201 197 187 173 170 159 156 142 129 127 116 105 98 91 85 73 67 64 58 52 37 29 20 Results Growth Rates H ybrid Walleye vs P urebred Walleye Growth in Weig ht 450 400 350 Phase I Early Lifestage Rearing Phase II Phase III Growout in Recycle System 300 G rams 250 200 150 100 S E -10 S E -09 WE -10 WE -09 50 0 April June Aug Days P os t Hatc h Nov March
Results Extended Growout Growth Rates Weig ht g ain of H ybrid Walleye R eared in R ec yc le S ys tem at 23 C 700 600 500 Growout phas e III-IV D GR =1.4 g/day G rams 400 300 200 F ingerling phas e II D GR =0.5 g/day 100 0 50 66 95 114 159 192 235 270 310 370 430 490 560 Da ys P ost Ha tc h
Results Overall Survival Percentages Intensive Rearing 100 % survival 90 80 70 60 50 40 30 Phase III Phase II Phase I 48% 48% >90% 0-38 mm 38-51 mm 51-102 mm 102-152 mm 152-239 mm 20 10 0 Phase and fish length
Novel Technology: RAS system Optimizing walleye stocking density and nutrient recycling in traditional and integrated aquaculture system
Novel Technology: Tank with attached RFS -solids removal -less water loss -less cost
Novel Technology:In tank lighting 24 hour belt feeder Covered tank
Novel Technology:In tank lighting
Low Density
High Density
Tank Density Growth Effect-Weight
Gregory Fischer Facility Operations Manager University of Wisconsin-Stevens Point Northern Aquaculture Demonstration Facility 36445 State Hwy 13 P.O. Box 165 Bayfield, WI 54814 Phone: 715-779-3461 aquaculture.uwsp.edu Subscribe to our Newsletter Email: gfischer@uwsp.edu