Grant: Strategic Projects - Group

The purpose of this proposal is provide immediately usable strategies to reduce the impact of viral hemorrhagic septicemia virus (VHSV) and at the same time generate novel tools and information in walleye, a highly valuable commercial species in the Great Lakes region. VHSV has long been associated with the European aquaculture industry but wasn't recognized in the freshwaters of North America until the spring of 2005 when a large-scale mortality event in freshwater drum occurred in Lake Ontario. Subsequently the causative virus was shown to be a novel strain of VHSV, unlike other North American or European strains. Mortality events in several species have continued in 2006/07. The discovery of this virus has had an immediate impact on fisheries management in central Canada. International and domestic regulations put in place to slow the spread of the virus have adversely affected normal aquaculture operations and practices. Additionally, fish enhancement stocking of walleye have been impeded, as fisheries managers try to stop the spread of virus. The effect of VHSV IVb on these stocked species of fish is not understood. VHSV IVb is also a serious concern to the angling industry with walleye, perch, muskellunge and several other species clinically affected. This proposal addresses some of the needed basic technologies and knowledge required to manage the effect of VHSV IVb, since the virus is now a fact of life in the Great Lakes. Firstly, alleye-derived cell lines to detect and propagate the virus will be sought. Secondly, infection trials will be done at different temperatures to determine the susceptibility of walleye to VHSV IVb. Managers could exploit this knowledge by basing stocking decisions on water temperature. This goal might also identify susceptible and resistant strains of walleye for increased survival after stocking. Finally some basic immune parameters of the fish strains will be characterized and correlated with temperature and survival following infection. This will allow managers to make decisions about the use of particular existing strains and the likelihood of stocking success.