An ecologist doing population counts in the estuary observes a drop in the number of trout over an extended period of time. What change is most likely
responsible for the trout decline?

answer choices:
Migration of blue herons out of the estuary area.
Introduction of a predator that feeds on blue heron eggs.

Algae → paramecium → mosquito larva → trout → blue heron

Implementation of new conservation laws to protect the
estuary

Application of insecticides to wet areas where mosquitoes
breed.