Once the eggs are put to bed, they need to stay undisturbed in the dark until they reach the "eyed" stage. We use an aluminum incubation box, and a half stack of heath trays. Except for checking the water supply and making sure no silt is being built up, there is not much to do during this stage. Once the eggs have reached the "eyed" stage, they are more durable and can be exposed to light. We determine it has reached that stage by keeping track of "ATU's" (Accumulated Thermal Units). We record the temperature every day, and add it to previous days. For chum salmon, the ATU's are approximately 300 to 350. For coho, they are approximately 300 to 500.
© 2003 Morten Creek Publications