This thesis is an investigation of the effect of water temperature on the patterns of growth and nutrient deposition in lake trout ('Salvelinus namaycush'), brook trout ('Salvelinus fontinalis') and F1 splake ('Salvelinus namaycush' * ' Salvelinus fontinalis'). Growth and feed intake increased (P < 0.05) with increased water temperature. When calculated as a percentage of live body weight, carcass composition was significantly (P < 0.05) affected by water temperature. When expressed on an absolute basis however, carcass composition increased in a linear manner as a function of increased body weight but not increased water temperature. Gross energy contents increased (P < 0.05) as water temperature increased and were best described by non-linear functions. Growth and carcass component data were used to successfully modify existing bioenergetic, feed requirement and waste outputs models; improving their applicability to stocks of lake trout, brook trout and F1 splake.