Ask the students to summarize what they have learned about the life cycle of salmon, the salmon's migration and limiting factors that affect salmon. Make sure the students have a clear working definition of limiting factors. Ask the students to give examples. This activity can easily be adapted to feature Atlantic rather than Pacific salmon. The most significant difference between these is that the Atlantic salmon can spawn more than once.
Many Atlantic salmon make their migratory journey and spawn two or three times.
All Pacific salmon die after spawning only once. To adapt the activity for Atlantic salmon, students are to make as many complete migratory trips as possible. After the activity is finished, ask students to report how many times they successfully completed the migratory cycle. Graph the data. Have the students explain how age influences mortality rates and susceptibility to limiting factors.