The Vermont Fish and Wildlife Department has been utilizing recirculating aquaculture systems (RAS) to rear walleye (Sander virteus) to produce fingerlings for stocking into Lake Champlain since 2011. Proof of concept techniques have been applied with successive production years to refine production procedures relating to feeding rates, the use of greenwater (algae) for turbidity, low light intensity throughout the larval production cycle and the utilization of self-cleaning tanks.
Fingerlings are reaching 50mm in length within 33-35dph. Analysis of oxytetracycline (OTC) otolith marking of stocked fingerlings is documenting that intensively cultured fingerlings have consistently outperformed fingerlings reared extensively using pond culture and that the recruitment of intensively reared fingerlings is making a significant contribution to the fishery. Reliable production output and elevated performance and recruitment resulting from intensive culture techniques using RAS will positively impact sport fish enhancement programs as well as forwarding potential commercial development of this species.