Spawning
Beginning near Halloween, staff check fish for sexual maturity. For the next 5 months the crew will spawn fish as they become ripe. Fish are first moved into the spawning house where they are anesthetized for easier handling. Ripe fish are placed on the sorting table, where one by one they are air spawned. The air spawning method involves inserting a needle in the females's abdomen to create pressure, pushing the eggs out for fertilization with sperm (milt) collected from a male fish. Milt is collected separately and added to eggs collected in the hatchery building. After fertilization, eggs undergo the triploid (PDF) process and are then placed into vertical flow incubator stacks, where they will continue to develop into fish.
Air Spawning female trout
Fertilized eggs in incubator tray
After roughly 35 days the egg will develop eyes. At this point most eggs are shipped, or moved into a hatching jar.
Fertilized eggs in hatching jars
Thirty more days and fish will begin to hatch. These times vary with water temperature. Mount Shasta Hatchery has cold water and it takes longer for eggs to hatch into fish.
After hatch, fry develop in the hatchery troughs until they are large enough to either be stocked into approved backcountry waters by airplane or pack animal (horse or mule), or are raised to larger "catchable" size for truck stocking to local waters.
Fingerlings in hatchery troughs
Inventory by weight count
Fish Stocking
Rainbow trout (Shasta strain) and Eagle Lake trout are planted as fingerlings by air and mule, and as catchable-sized fish to roadside waters by truck.
Every year approved lakes are stocked by air to waters inaccessible by vehicle.
Fish delivery to CDFW airplane
Historic photo of aerial stocking
During the spring and summer months Mount Shasta Hatchery stocks catchable trout in approved local waters by truck.
Loading a truck for stocking
In select places, pack animals or ATVs are used for fish stocking
Backcountry Horsemen often assist Mount Shasta Hatchery to stock high mountain lakes