Subject

Life Science

 

Objectives

To help students understand food chains and specifically the food chain of salmon and trout.

 

Materials

• Salmon Food Chain Cutouts
• Trout are made of trees by April Pulley Sayre
• Crayons, markers and/or colored pencils
• Yarn
• Scissors
• Hole punch tool

 

Background

The book Trout are Made of Trees is a great story to help students understand the food chain of trout and therefore salmon as well.

The health of a stream depends on many factors, including vegetation, surrounding land, forest cover, and substrate. Decomposing leaves in the streams, which have fallen from the surrounding trees, are what start the stream food chains and food webs. Bacteria and fungi feed on dead plant material. Herbivorous stream invertebrates feed on bacteria, fungi, algae, and partially decomposed leaves. These invertebrates then become food for predators, such as benthic stream macroinvertebrates, reptiles, amphibians, trout and other fish. These animals often then become food for animals higher up in the trophic system such as birds of prey, mammals, and even humans. This entire food chain is fueled by energy from the sun that fuel the trees.

When talking about salmon and their food chain it is also important to mention the importance of salmon for the health of the trees. Spawning salmon die after spawning. Their bodies then decompose and provide nutrients for the trees and other vegetation, as well as feeding bacteria and even their hatched salmon fry.

 

Procedure

1. Prepare the yarn. Each student will need a string about 25” with a knot or loop tied at the end.
2. Ask students to think about the streams that salmon and trout live in. What do they look like? What is important to help them survive? What things eat salmon and trout?
3. Introduce the following terms: predator, prey, herbivore, carnivore, macroinvertebrates
4. Read Trout are Made of Trees by April Pulley Sayre. Discuss the title beforehand and ask students what they think it means.
5. Discuss how trout fit into a stream food chain, including how the sun provided the energy for the trees and plants to grow, how the leaves fall in the water and provide food for bacteria and herbivorous invertebrates, macroinvertebrates feed on the smaller invertebrates, trout feed on the macroinvertebrates, and larger predators feed on the trout.
6. Pass out the Salmon Food Chain Cutouts and ask the students to color them and cut them out
7. Have the students put the cut outs in the correct order (sun, tree, caddisfly, stonefly, trout, great blue heron, otter).
8. Help them punch two holes in each cut out, and show them how to weave the yarn to have all the pictures facing the correct direction on the yarn.