Salmon A Link in the Food Chain

Salmon A Link in the Food Chain

A Chain of Life Imagine a chain. Each link is connected to the next. One link cannot be broken without affecting the other links in the chain. Salmon are links in many different food chains. As salmon go through the stages of their life, they eat and are eaten by different living things.

Let's look at the food chain for an adult salmon. It begins with plankton, tiny living organisms. Plankton are eaten by small fish such as herring. Herring are then eaten by salmon. A salmon may be eaten by a human, a bear, a killer whale, a seal, or an eagle. Harming one living thing in a food chain harms other living things in the chain.

Salmon are travelers. They start their lives in streams or rivers, migrate far into the ocean, and return to the very same place to spawn, or reproduce. Salmon are transformers. During a salmon's life, it will change shape and color numerous times. In this book, you will learn about the salmon life cycle and about all the ways they are interconnected with other animals and with their environment.

Eggs Salmon begin as tiny eggs laid in the gravel of a riverbed or streambed. Salmon need cold, clean water in order to lay and fertilize eggs. If the temperature is too warm, the salmon may die before the eggs are laid. Salmon absorb oxygen from the water, so if the water is polluted, making it low in oxygen, salmon cannot breathe and will die. Water is a salmon's environment, and if it is harmed, salmon and the eggs they lay will be, too.

Alevins and Fry After about two weeks, the eggs hatch. The tiny salmon that emerge, called alevins (AL-uh-vins), have their food attached to their underbellies in a sac. Once the sac is empty, the alevins develop stripes and are called fry.