What is a key characteristic of moderately sensitive species?

• A. They can only survive in freshwater
• B. They are indicators of non-polluted water
• C. They cannot survive in any polluted water
• D. They can survive in slightly polluted water

Answer: (D)

Moderately sensitive species exhibit a degree of resilience to changes in water quality, meaning they can tolerate some pollution but not extreme conditions. This characteristic allows them to survive in slightly polluted water, which often indicates that the ecosystem is undergoing stress but not in a state of severe degradation. Their presence can help assess water quality, as they are not as hardy as highly tolerant species, yet not as vulnerable as highly sensitive species. Thus, their survival in slightly polluted environments makes them valuable indicators of moderate water quality, assisting in evaluating the health of aquatic ecosystems.