Question

hunting ospreys and bald eagles is currently illegal in the united states. if laws were changed to allow humans to hunt these birds, their populations would likely decline significantly. since changes in the population of any tertiary consumer can impact the entire food web, which of the following outcomes is the most direct result of a decrease in eagle and osprey populations?
decreased populations of tundra swans and vegetation
decreased populations of phytoplankton and vegetation
increased populations of sea ducks and large piscivorous fish

Explanation:

Ospreys and bald eagles are tertiary consumers (top predators) that likely prey on sea ducks and large piscivorous fish. If their population decreases, the organisms they prey on (sea ducks, large piscivorous fish) will experience less predation pressure, so their populations are expected to increase. The other options suggest decreases, which is inconsistent with the removal of a top predator (the prey of the top predator should increase, not decrease).

Answer:

increased populations of sea ducks and large piscivorous fish