Why are giant water bug populations considered an important indicator for scientists studying freshwater health?

Answer

They are high-level predators whose status depends on the health of the entire aquatic community below them

As high-level predators, the presence and health of giant water bug populations are intimately linked to the overall balance of invertebrates, amphibians, and small fish within the aquatic community.

Why are giant water bug populations considered an important indicator for scientists studying freshwater health?
fooddietinsectwaterbug