Question

The data shows that recently the shark population increased. How will the increase in the shark population affect the other populations? Be sure to explain whether the sea otter population, the sea star population, and the clam population will change, and why.

Answer 1

Answer: This will start a trophic cascade.

- Sea otters: decrease. An increase in sharks means more predation on otters (a direct negative effect), so the otter population will fall.
- Sea stars: increase. With fewer otters preying on or controlling sea star numbers, sea stars are released from that pressure and their population will rise (an indirect effect of the shark increase).
- Clams: decrease. More sea stars means stronger predation on clams, so the clam population will decline.

Note: these are the expected directional changes given the food‑web links (sharks → otters → sea stars → clams). The timing and magnitude depend on how strong those interactions are and on other factors (habitat, disease, fishing, carrying capacity), but the sign of each change follows from the direct and indirect predator–prey relationships.