In 2020, the Illinois-Indiana Sea Grant (IL-IN SG) program formed a Walleye working group and held a workshop to determine the marketing and production barriers to a walleye industry. On the production side, the most pressing barriers were access to feed trained fingerlings and a reliable domesticated source of walleye brood stock. In years 2020-22 at the Aquaculture Research Lab (ARL), domesticated walleye held in ponds under natural conditions were spawned indoors and the resulting eggs incubated. Hatched fry was stocked into prepared earthen ponds feeding of planktonic organisms for approximately one month and harvested at approximately one inch in size. Fingerlings were stocked in a three-tank recirculating system and feed trained using Otohime® feeds before switching over to a commercial walleye diet. Fingerlings are generally sold at 6 months of age in the fall with a portion held back for future brood stock.
Procedures for the above production generally followed the protocols outlined the Walleye Culture Manual from the North Central Regional Aquaculture Center (NCRAC). Production of walleye fingerlings has been either pond based as described above or can be done wholly indoors using methods described in the University of Stevens Point Northern Aquaculture Demonstration Facility (UWSP-NADF) Walleye Culture Guide. In 2023, IL-IN SG funded research to determine if pond harvested fingerlings could be feed trained in pond-side tanks circulating pond water to remove waste products. Although survival was not as high (0-63%) when compared with indoor RAS systems (85-90%), there is significant saving on infrastructure costs.
In 2024, using eggs obtained from Genoa National Fish Hatchery and Minnesota Muskie, fry was stocked in ponds and two pond-side tanks. Pond-side tanks were reared under protocols similar to NADF with the exception that the turbidity was provided by natural pond water. Feeding commences one day post stocking with Otohime. Survival was relatively low at 10 and 37%. Progeny from this year class is to provide future brood stock the Blue Waters farm in Minnesota.