Question

Imagine that you are an ecologist who must determine whether an entire river and lake biome is being threatened by human activity. What might you look for in an indicator species?

a. One that has been introduced to the biome

b. One that lives off of the biome's water-loving trees

c. One that is most easily affected by changes in water quality

d. One that you are most familiar with, and for which you can judge health by appearance of fur or other outward indicators