Development of Thermally-Enhanced Walleye Aquaculture

Abstract

The culture of walleye in Minnesota can be enhanced by the use of heated waters. Wild-caught walleye fingerlings were maintained in the Aquaculture Research Facility at Minnesota Power's Clay-Boswell Plant. These fingerlings were subsequently induced to feed on a pelleted dry feed and to grow, increasing their size 8.8 times. Fingerling mortality within the facility after conversion to dry diet was minimal. Feed conversion (food fed to body weight increase) ranged from 2.2 to 3.2 over the project's duration. Growth predictions from walleye bioenergetics models, developed for each of the strains in the Aquaculture Research Facility, were extremely close to actual growth in the facility (within 2%). Because of the short duration of the project, it is too early to assess the walleye model's ability to predict mortality and food conversion efficiency. However, initial inspection suggests that it may predict walleye mortality (after fish have switched to dry diet) quite well, but does not predict food conversion well at this point. The walleye bioenergetics model appears to provide a means of detecting growth differences in different strains of walleye, which could be extremely valuable in choosing faster growing strains for future culture.