Some fish spend their lives in both fresh water and salt water. Fish (like salmon) that hatch in fresh water and migrate to live the majority of their lives in the ocean before returning to fresh water to spawn are called “Anadromous”.
Anadromous fish lead an interesting life as you can imagine and their lives take place in a variety of different environments that include streams, estuaries and the Ocean. Life begins with the hatching of the salmon egg. The female salmon lays anywhere from 500 to 1200 eggs which are deposited in a nest and fertilized. Of the 500 to 1200 eggs only about 20% will survive to become fry.
The eggs hatch in late winter and the salmon fry begin to feed. Different species will spend different amounts of time in fresh water before finally migrating to the Ocean. Sockeye, for instance, spend the longest period of time in fresh water remaining from one to three years, while on the other end of the scale Chum and Pink Salmon migrate almost immediately downstream in their trek to the ocean.