Teacher’s Questions for When the Nose No Longer Knows


Before reading:

1. Do you think fish have a strong sense of smell? Explain your answer. What types of things do you think fish use their sense of smell for?

During reading:

1. How do baby fish find their homes around islands like Kimbe?

2. List four things that fish use their sense of smell for.

3. Why is the chemistry of lakes and rivers changing? Why is the chemistry of the ocean changing?

4. Explain how a fish detects a scent.

5. How is copper getting into rivers?

6. What is Schreckstoff? How is it released? What does it signal to fish?

7. When fish are exposed to copper, how do they react to Schreckstoff in the water?

8. What gas does the ocean surface absorb, making seawater more acidic?

9. Describe two ways that acidified seawater affected baby clown fishes’ sense of smell in Dixson’s experiments.

10. Does acidified water affect only a fish’s nose, or does it affect other parts of a fish? How did Munday’s experiments determine this?

11. How do hermit crabs find and choose their shells?

12. What happened when hermit crabs exposed to acidified water were presented with shells and food?

After reading:

1. The changes to fishes’ sense of smell described in the story are a matter of life and death for the animals. Describe two ways in which your life would be different if you had an impaired sense of smell. Would these changes put you in harm’s way?


1. Were you surprised to learn that human activity can affect fishes’ sense of smell? What are two things you could do to lessen your contribution of chemicals that damage fishes’ sense of smell?