During spawning, eggs are deposited by the female in redd then male fertilizes the egg with his sperm. Each nest contains 500 to 1200 eggs, only 20 out of 100 actually live to move on to a alevins stage. Many die before hatching, some die because they didn't get fertilized, some because of disease. It depends on the tempeture of the water when the eggs are going to hatch it could take 6 to 12 weeks. Salmon life span is 2-7 years 4-5 is the average. Salmon eat insects when they are young and start to eat other fish when they get older.