The graph illustrates the salmon’s life cycle.
Overall, there are three phases in total of the salmon’s life, from a small fry up to an adult salmon. The cycle lasts around nine and a half years, over the course of three areas corresponding to each phase of the salmon’s life.
At the start of their lives, salmon fry hatches from eggs typically laid by their parents in the upper rivers, among the reeds, where the water is slow moving. After around half a year, the fry move on to the lower rivers and stay there for around four years, this is the second phase of their life where they grow from a 3-8 centimeters fry to a 12-15 centimeters smolt, the river here is now much more fast flowing compared to their birth place.
From here, they continue their journey to the open sea and here is where they will mature into adulthood, they will continue their life for around 5 years until they finally return back to where they come from, through the fast flowing lower river, up until the upper river to lay eggs. That is the life cycle of a salmon.