Research and Projects - Coded Wire Tagging Program:
1. Hatchery Building – In here you will find incubators and tanks. After spawning, the eggs are brought here to be washed and put into incubators. The water flows in at the top (of the incubator racks), through each tray, and out the bottom (of the rack). Approximately six weeks after fertilization, the egg hatches into yolk-sac fry. The fry, whose sole source of food is the yolk-sac, remain in the incubators until the sac is absorbed, approximately 5-6 weeks. Ideal temperature is 54° F (12°C) for proper incubation. After hatching, the young salmon are place outside into ponds for initial feeding. The young steelhead are placed into the green tanks (in the hatchery building) where they begin grow-out until mid-June. Final grow out of steelhead is accomplished in the 15’ X 150’ raceways.
2. Large Rearing Raceways – Juvenile salmon are placed in these ponds after 30 days in the nursery ponds. They are fed a diet rich in protein and lipids, primarily composed of fish meal and oil and supplemented with essential vitamins and minerals. In April, Fall Chinook Salmon are released into Battle Creek. Fall Chinook are approximately three inches long at release and 90 of these fish equal a pound. The steelhead trout are reared in large raceways from June until January and released directly into the Sacramento River at an approximate length of 8-10 inches.
3. Spawning and Visitor Viewing Area – Spawning operations may be viewed twice per week during the spawning season (October through March). The fish, ranging from 5-60lbs, are anesthetized with carbon dioxide and checked for ripeness on the sorting table. The ripe salmon are killed, sorted by sex, and sent to the spawning table. On the spawning table, females are hung by the jaw and a needled is injected into the abdomen (for air injection). This process allows for efficient egg extraction. Milk is extracted from the males and mixed with eggs for fertilization.
4. Holding Ponds – The fish are held here between spawning days. You will see salmon and steelhead in these ponds. Fish are separated on the sorting table (inside the spawning building).
5. Fish Ladder – Salmon and steelhead swim and jump up the fish ladder from Battle Creek. The many steps in the ladder provide areas for fish to jump up and deep pools for resting.
6. Battle Creek – Salmon and steelhead come into the creek from the Sacramento River. Approximately 95% of the returning fish originated at the hatchery (based on coded wire tag and marked fish returns). The upstream fish ladder (located next to the barrier weir) allows for fish passage between March and August. During the remaining months fish are diverted into the hatchery.
7. Water Treatment Facility (Ozone generation plant) – All fish production water originated from Battle Creek and contains fish pathogens. Before the water is used for fish culture it is filtered, treated with ozone, and stripped of ozone. The ozone kills all pathenogenic organisms.