Understanding Dams and Their Impact

What is the primary purpose of a salmon cannon?

• To capture salmon for research

• To prevent salmon from migrating

• To transport salmon downstream

• To shoot salmon upriver

What percentage of the world's electricity is generated by hydroelectric energy?

• 10%

• 16%

• 70%

• 25%

Which of the following is NOT a negative consequence of dams on ecosystems?

• Increased water temperature

• Improved fish migration

• Toxic water accumulation

• Disrupted sediment flow

What is one of the main reasons salmon populations have been declining?

• Pollution

• Overfishing

• Installation of dams

• Climate change

Which of the following is NOT a method used to help fish migrate past dams?

• Fish cannons

• Fish nets

• Fish ladders

• Fish elevators

What is a significant benefit of removing a dam?

• Enhanced flood control

• Increased water storage

• Restoration of natural river ecosystems

• Improved recreational opportunities

Which river's dam removal is considered a major success story?

• Elwha River

• Mississippi River

• Colorado River

• Columbia River

Why is it unrealistic to remove all dams?

• They are too large to dismantle

• They are protected by law

• They are too expensive to remove

• They provide essential resources like water and energy

What role do beavers play in the ecosystem after dam removal?

• They build new dams

• They transport seeds and alter waterflow

• They prevent fish migration

• They increase water pollution

What is a realistic approach to managing existing dams?

• Building more dams

• Removing all dams

• Ignoring environmental impacts

• Making them more environmentally friendly