Walleye Larviculture in Water Reuse Aquaculture Systems

Meeting of the three authors during the 2011 Midwest Fish and Wildlife Conference in Des Moines, Iowa, led to frequent communication that formed the basis for collaborating on the status of their respective production facilities. The operation techniques of the water reuse aquaculture system (RAS) facilities in Vermont and Iowa are compared and contrasted. Kelsey and Johnson present detailed descriptions of Walleye (Stizostedion vitreum) larviculture in innovative RASs at the fish culture facilities in Vermont and Iowa, respectively. Since 2011, intensive culture of Walleye fry/fingerlings has been conducted at the Ed Weed Fish Culture Station in Grand Isle, Vermont, with the goal of large-scale production from the facility’s program inception to supplement existing extensive pond culture efforts of fingerlings that are used for sports fishing restoration. Tank volumes of 1940 L are now used in a RAS dedicated exclusively for intensive Walleye culture. Proof-of-concept techniques have been applied with successive production years to duplicate identified advances related to feed and feeding rates as well as various rearing environment conditions. After two successive years of trials in four self-cleaning tanks (2018 and 2019), as of 2020 all tanks within the system are now self-cleaning, providing optimum rearing conditions. The feeding of blended feeds through the entire culture run has also been applied since 2017. Larviculture survivals from day 1 post hatch (1 dph) through 34 dph in excess of 60% are being achieved averaging 50 mm in length, providing recruitment to the fishery that can be documented.