The diagram illustrates the stages in the life cycle of a salmon, from birth to maturity.
Overall, it is clear that life cycle of salmon is largely natural and cyclical process which can be generally categorized into three main stages: the early stage, the juvenile stage, and the adult stage.
The first stage happens in the upper river. Salmon begin their lives in rivers where they lay and incubate their eggs. The eggs are laid among small stones and reeds. After a while, the eggs turning into fish called “fry”, which are about 3 to 8 cm long. The fry stays in the upper river for about 5 to 6 months, feeding and growing before they move on.
The second stage takes place in the lower river. They live there for about 4 years, and during this period, they grow bigger for about 12 -15 cm. The fish slowly change so they can survive in saltwater. Once they are ready, the smolts leave the river and swim into the sea.
The third stage occurs in the open sea. The salmon growth into full-sized fish, reaching 70 to 76 cm in length. They live in the open sea for about 5 years. Finally, the adult fish travel back to upstream to spawning areas of rivers, here they reproduce and lay their eggs, and a life cycle begins anew.