The three flow diagrams illustrate the stages in the life of the salmon, from birth to maturity.
It is clear that there are three main stages as the salmon develops from egg to mature adult. We can also see the salmon spend time in three distinct locations during their life cycle, moving from the upper river to the lower river to the ocean, and then back upstream.
The adult salmon lay and incubate their eggs among small stones beneath reeds in the upper river. After emerging from eggs the young salmon which are called fry, spend approximately five or six months in this slow-moving river. They then swim to the fast-flowing lower river, where they continue to grow and develop for about four years.
Following this rearing period in the lower river, the maturing salmon, known as smolt, migrate to the ocean, where they eventually become fully grown adult. Finally, the adult salmon return to the upper river to reproduce and lay their eggs, beginning the cycle anew.