North Cascades

Salmon of the Skagit River Watershed

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Background A productive salmon water system needs to have pools, riffles, side channels, and woody debris. Pools are a crucial factors because they offer hiding places amongst boulders and woody debris for young fish and areas of respite for migrating adults. Riffle and rapid areas mix air with the water, thereby increasing the oxygen content of the water; these areas support a richer concentration of aquatic insect larvae (salmon food) than slower moving parts of the water system. Woody debris creates riffles and rapids, and contributes to the formation of pools. The debris also gives aquatic insects shelter. Side channels are rich in aquatic insect life and are important habitats for juvenile salmon. These areas also provide places of escape for juvenile during high water. Method The students will play a game which displays how streamside, also known as riparian, vegetation is crucial to the survival of juvenile salmon.

SUBJECTS Science, Social studies, Art OBJECTIVES The students will understand that streamside vegetation is a critical component of salmon habitat as a source of shelter. VOCABULARY Habitat, Predator MATERIALS Paper and colored pencils Copy of lists made in Activity #1 Two pieces of rope to represent a stream Portable blackboard or dry erase board SIZE / SETTING / DURATION Whole class Indoor classroom for Activity #1 and large open area or playing field for Activity #2 1 hour for Activity #1 and 1 hour for Activity #2

The instructor may also choose to take the class to a salmon stream or have the students go outside of class time.

1. Ask students to draw a picture of a stream habitat that would provide young salmon with protection from predators. The aforementioned photos would be useful here.

2. After they have drawn their sheltering habitat, list the shelters they provided on the blackboard/or dry erase board.

3. Discuss how the various shelters might protect young salmon from predators and from currents. If students don't mention them, add and discuss the effects of logs, brush, shadows, camouflage, undercut banks, rocks, aquatic plants, etc.

4. Use the blackboard/dry erase board to list the various predators mentioned by the students and match each to the type of shelter that protects young salmon from these predators.

5. Divide the shelters into "in stream" and "out of stream" columns.

6. Circle the shelters that humans affect the most. Star the ones that we can easily replace.

7. Discuss how shelters would differ in urban streams, mountain streams, slow streams, and fast moving streams.

8. Discuss how shelters might differ in timber, agricultural/rural areas, or urban settings. You could compare what shelters could be provided for fish in their backyards, next to shopping centers, livestock pastures, deep forest, etc.

9. Explore other aspects of damage to the habitat quality caused by removal of different types of shelter. Examples include increased water temperature, erosion, and decreased food as a result of vegetation removal, and streambed erosion as a result of the removal of large rocks.

It is important to carefully and completely read the directions and understand them before beginning the activity.

1. Review the list for Activity #1: the variety of predators and shelters for young salmon.

2. Divide class into four groups. Group 1, made up of 2-4 students, will be the ecologists. Group 2 will be the coho fry living in the stream for a year after hatching. Group 3 will be a group of 3-5 individuals that represent predators (raccoons, larger fish, humans, great blue herons). Group 4 will be various shelters (logs, brush, shadows, aquatic plants, undercut banks). Groups 2 and 4 should be rather large, try having more salmon than shelter and then try having more shelter than salmon.

3. Explain to the ecologists, Group 1, that they will need to be very observant. Have them make separate lists of the people who are portraying predators and shelters from their observations. (You may add more ecologists if the 2-4 students will have a difficult time trying to record data.)

4. Meet with the fry, predator, and shelter characters. Have the predators and shelters assign or draw roles. Discuss how the shelters can portray their roles: an overhanging bush would stand upright with their arms bowed over the stream, aquatic plants would be on their hands and knees so the salmon could crawl under them or hide right next to them. Make sure the salmon fry actors/actresses can identify the different kinds of shelter and understand how a salmon would use the shelters.

5. Identify the boundaries of the activity and spread the rope out to show the location of the stream.

6. Tell the predators that they cannot grab the fry if they are close to the shelters.

7. Ask the ecologists to watch closely so they can identify the kinds of shelters and predators that are being portrayed. Make sure that none of the salmon are taken by predators while they are in a shelter.

8. Encourage the students to really take on their roles with fish faces, predator growls, have the shelters sway with the movement of the river and make sounds of the moving water. Do you have a tape of water that you could play?

9. Let the students know that the role playing stops when you give the signal (blow the whistle?) but don't let them know how long this will be. Place the shelters along the stream, send the salmon fry into the stream, and then turn the predators loose for a 30 second to one minute period. Salmon that are caught will sit down with the ecologists.

10. Ask the ecologists what the different roles were. Ask for suggestions on how students could better portray their roles. Discuss how brush must be shaped to provide shelter, how banks overhang, how rocks provide services (slow down the water, create places of slow water on the downstream side), etc. Help them to visualize the shelters.

11. Start the role playing again. You can start from the beginning and bring all the fry back to life. Stop the action when a few fry are caught.

12. Discuss the following with the students:
    • What happened to the fry that didn't have any shelter?
    • Were there any fry that didn't leave their shelter? What would eventually happen if a real coho salmon fry never left its shelter?
    • Which shelters protected fry from other fish?
    • Which shelters protected fry from land animals?
    • What shelters protected fry from humans?
    • What would the predators do if there weren't any fry to eat?
    • What would the fry do if there weren't any predators to eat them?

13. Set up the role play again, but before you start, explain that you want to clean up the stream and remove logs, bushes, and trees. Have these actors/actresses sit with the ecologists.

14. Discuss the following with the students:
    • Ask the ecologists about the results of the cleanup.
    • Do humans damage streams without knowing it?
    • How can humans help repair stream shelters?

15. Gather the students into a group. Discuss how the game would be played differently if the fry were spawning salmon.
    • Which shelters wouldn't be used by spawning salmon?
    • Which predators should not be a problem for spawning salmon?
    • Which predators can they think of that prey on spawning salmon?
    • What animals eat the spawned out salmon?
    • What would be the most important shelter for a spawning salmon?