| Contents Notes |
The use of heated seawater for enhancing the culture of Pacific salmon was investigated. Food consumption rate, gross food conversion efficiency, growth rate, and survival of chum (Oncorhynchus keta) and pink (O. gorbuscha} salmon fed to satiation were determined in relation to water temperature and body weight. Both species of salmon were raised at temperatures of 55À, 60À, 65À, and 70ÀF. The highest food consumption rate, gross food conversion efficiency, growth rate, and survival of chum salmon occurred at temperatures of 65À, 55À, 55À-65À, and 55ÀF, respectively, while those of pink salmon occurred at 65À, 55À-65À, 60À-65À and 55 -60ÀF, respectivety. The response to all conditions measured was poorest for chum and pink salmon at 70ÀF. Pink salmon generally had a higher food consumption rate, gross food conversion efficiency, and growth rate than chum salmon. Food consumption rate, gross food conversion efficiency, growth rate, and survival of chum and pink salmon decreased as body weight increased. As body weight increased, food consumption rate, gross food conversion efficiency, and growth rate generally decreased more at 60À-65ÀF than at 55ÀF for chum salmon, and more at 65À-70ÀF than at lower temperatures for pink salmon. Survival was influenced by behavior and disease in addition to temperature. Diseases encountered were bacterial kidney disease and vibriosis, of which the former was most prevalent. Chum and pink salmon can be cultured in heated seawater at temperatures not exceeding 65ÀF. Good growth (>5% gain in body weight/day) and survival (60-100%) can be expected. |
