Essay on The Pacific Salmon Life Cycle

1037 Words Nov 18th, 2016 5 Pages
1) Pacific Salmon Life Cycle
a) As it stands, man-made dams disrupt the complex and specific life cycle of the Pacific salmon. Dams impact and affect the pivotal reproduction of the salmon species by causing a disturbance in the pattern of migration during the reproductive season. The Pacific salmon goes through two miracles in its lifetime of transformations of changing its entire system to go form fresh water to salt water. The miracles of the fish bodies adapting to the change in environment are caused by migration for dietary and security reasons. Salmon migrate from a young age from freshwater streams into the ocean because of an abundance of food and less predators to increase the probability of growing to mature reproductive age. Salmons travel to the ocean as a result of evolutionary pressure since oceans provide food, but not productive areas for reproducing. As such, salmons have to return to the stream they were born in to reproduce. Since salmon can only reproduce once and only reproduce in their original stream, dams and pollution that change the chemical composition of the water makes the fish get lost. Since fish rely on the current and chemical composition of the water, dams and pollution and physical barriers negatively impact the migration of the salmon.
b) The life cycle begins with salmon being hatched in slowly moving, deeper areas of water in freshwater streams and rivers. After hatching the fish become “alevins” that still have yolk sacs attached to…

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