The three stages in the life cycle of a salmon are shown in the diagram.
The first stage of the process begins with the adult salmon laying its eggs in the reeds among the small stones. These reeds are located in the upper river which is slow moving. It takes around 5 to 6 months for the eggs to hatch.
The young fry measure between 3 to 8 cm and swim to the lower river which is fast flowing. They inhabit this area for approximately 4 years in which their sizes increases to between 12 and 15 cm.
The smolt then swims to the open sea and remains there for around 5 years. In this environment it reaches its full adult size of 70-76 cm. It is now referred to as salmon in this stage of development and makes its journey back to the upper river in order to lay eggs once again.
We can see that salmon live in three different areas during their life time increasing in size in each habitat. The whole process from egg to adult takes around nine and a half years.
Question taken from Cambridge IELTS 10 p.101
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