Salmon Homing Instincts
activity exercisesuggested grade levels: 7-8
view Idaho achievement standards for this lesson

Overview:
Some Salmon species are born in streams and rivers of the western United States. These fish hatch in the headwaters of many of Idaho's rivers and then travel to the sea. In the ocean they eat and grow for a period of four to five years. At maturity they return to breed and lay eggs in the streams where they were born. Returning salmon use chemical cues and probably a variety of other senses to find their way up hundreds or even thousands of miles to their place of birth. Students should have some background on the lives of Salmon and their long migrations back to their breeding grounds. The Digital Atlas is an excellent resource for this because there is a PowerPoint presentation constructed for teachers. To get there: Click on Atlas Home, Hydrology, Game Fisheries, then on Salmon Presentation.

Objectives:
1. Students will be exposed to the Digital Atlas.
2. Students will learn how Salmon return to their native streams.
3. Students will be aware of barriers that salmon will face.

Materials:
Index Cards A variety of smelling compounds (perfume, cinnamon, vanilla, etc. Have at least 5 different scents.) Digital Atlas

Procedure:
1. Present the PowerPoint presentation to the class titled "Salmon Presentation" (see above). Talk about the life of a salmon. Be sure to mention the influence of mankind on the salmon population.

2. Rub a smelling compound on each of the cards so each card smells, make at least five cards with each scent and have this done before class (5 vanilla, 5 perfume, etc). Use these smells to represent the scents of various streams that salmon use to return to their breeding grounds. Each river or stream will have its own particular scent. On the back each card write one of the various fates that await salmon along their journey. Examples include, eaten by bear, stopped by dam, poisoned by pollution, make it safely to breeding grounds, etc. Group these cards together by smells. Each group of cards with the same smell represents a river or stream. Place each "river" or group of cards in a different location in the classroom.

3. Assign each student to a scent, (vanilla, cinnamon, etc. Many students will get assigned the same scent because there are only 5 different scents). Explain to the students that each student represents a fish and each fish must find its own river which leads to its breeding grounds. Each "fish" will find its "river" by smelling the groups of cards. When a "fish" finds a group of cards (river) that match its assigned scent, it has reached its correct river and can swim upstream

4. To swim upstream, each "fish" will select a card from the group of cards and turn it over and read what it says to determine its fate. Some fish will make it safely while most others will not.

5. Take a tally to see how many students made it safely to their breeding grounds.

6. Have class discussion on problems that salmon can face when returning to their breeding grounds; include both man-made and natural.

Handouts/Activity links:
These are links to access the handouts and printable materials.
Salmon Presentation

Related Lesson Topics:
Biology: Fish
Biology: Biology Topics

Lesson plan by Stefan Sommer and James Scannell, 2001
Idaho Achievement Standards (as of 7/2001) met by completing this activity:
798.01
802.01
803.01.02
808.01