Grant: Strategic Projects - Group

Aquaculture is recognized as a growing source of employment and offers the possibility for social and economic improvements in communities with limited industrial alternatives. Ontario is the major Canadian producer of rainbow trout for human consumption. Young trout (called seedstock) are produced from adult breeders (broodstock) and reared for several months in land-based hatcheries. They are then transported to cages in Georgian Bay and the North Channel of Lake Huron where they are grown over the summer and harvested. Even though market demand and consumer acceptability for Ontario trout is very strong, imports of farmed fish products dominate the marketplace. The major producer of seedstock in Ontario (Lyndon Fish Hatcheries Inc., New Dundee, Ontario) is unable to meet the demand for seedstock to be grown in cages. The development of Canadian trout aquaculture is limited by the ever increasing summer temperatures that the fish are being exposed to in the cages. Increased water temperatures lead to stress and as a result the fish do not feed and grow for four weeks or more - fillet yield can be reduced by up to 25%. Our proposed research will use two inter-related strategies expedite the development and availability of rainbow trout that are suited to culture at higher water temperatures. First, we will identify genetic markers that are associated with increased tolerance to thermal stress. This will facilitate the genetic improvement of the Lyndon rainbow trout broodstock and thus increase productivity of the Ontario industry. Second, we will explore a novel approach where young fish are pre-conditioned to mild thermal stress and test whether they are able to resist stress when they are older. This project involves groups from two Canadian universities and two supporting organizations. This concerted effort is an example of an advanced biotechnology being applied to enhance the capability of one of Canada's resource based industries, namely aquaculture.