Lesson 1 Human Impact on Local Ecosystems

The Disappearance of Fraser River Salmon

Learning Outcome

Students evaluate the human impacts on local ecosystems.

Steps to the Lesson

  1. Preview a list of phrases from a video presentation.
  2. Watch a video on Salmon Disappearance in the Fraser River.
  3. Complete a Thinking Yes/Thinking No activity on an issue concerning the Fraser River.
  4. Complete a Hotseat debate activity.
  5. Reflect on new understanding.



Students will:

  • gain an understanding of how people impact local salmon ecosystems.
  • develop an awareness of the complexity of the issue surrounding salmon disappearance.
  • understand different perspectives by taking on the role of various stakeholders in the salmon fishery.


Students will demonstrate their understanding of the human impact on local salmon ecosystems through an informal debate.

Activate Prior Knowledge:

Distribute sheet containing a list of phrases which come directly from a video presentation discussing the disappearance of the Fraser River salmon. In partners or small groups, students answer and complete the Before section of the phrase sheet in anticipation of the video presentation.

Predict and Question:

Ask the students what questions they may still have regarding how human populations impact local salmon ecosystems. What are they wondering about?



Reminder: It is important to stop throughout the video and give students (A/B partners) opportunity to talk or respond to the video.


The Disappearance of Fraser River Salmon

(Video Length: 6 mins)

Distribute the following articles on the Fraser River. The first article gives factual information about the Fraser River and the second article focuses on the human impact imposed on the Fraser River.

Fraser Facts

Threats Facing the Fraser River

While reading the articles, students need to identify what they feel are five important facts from each article. (Note: This can be done by hilighting text on the printed article or writing on the back of the article pages)

After reading the articles, encourage student discussion about the issues facing the Fraser River. Complete a Thinking Yes/Thinking No sheet using A/B partners and consider the question:

“The Damming of Fraser River tributaries is essential to meet the hydroelectric needs of the BC Lower Mainland.”

Students should consider the ‘Thinking Yes’ side to include the hydroelectric dam companies and their employees. The ‘Thinking No’ side could include local fishermen and environmentalists.


Using a ‘Hotseat’ activity, students take on the role of various stakeholders that would be affected by pollution, global warming, disappearing tributaries and the erosion of the Fraser River.

In groups of three or six (three groups of partners), each student (or student pair) takes the role of either the salmon, a construction developer, or an environmentalist. On their ‘Hot Seat’ sheet, students record reasons why they would be concerned about the issues affecting the Fraser River. Once the students have prepared their positions on the issue, the students take turns presenting their side of the issue, allowing for a brief rebuttal from the other two groups. The activity is concluded once each student/student pair has had a chance to present their position in their role.


Using a Reflection Wheel, students summarize in written form and/or illustration, one of the following:

  • four ways that they will be more aware of their environment.
  • four things they learned from the lesson.
  • four ways that they can contribute to deal with the issues discussed in the lesson.