Ecologist Dr. Wright argues that the decline of a specific freshwater mussel species is caused not by water pollution, as is widely assumed, but by the loss of host fish needed to complete the mussel's life cycle.
Which finding, if true, would most strongly support Dr. Wright's argument?
- A
Some mussel species are sensitive to changes in water temperature.
- B
Many freshwater habitats have experienced pollution events in recent decades.
- C
Freshwater mussels can live for many decades.
- Dcheck_circle
Streams where mussel populations declined sharply also experienced steep declines in their host fish, even though water quality has remained stable; clean streams without host fish have likewise shown mussel declines.
Explanation
A holds water quality constant and isolates host-fish loss as the variable that tracks mussel decline. B, C, and D are tangential.