Question

Species that serve as early warnings of environmental damage are called

• A. Keystone species
• B. Native species
• C. Specialist species
• D. Indicator species

Hint:

Remember that "Indicator" species point to or indicate the health of an ecosystem. For example, the presence of stonefly and mayfly nymphs in a stream indicates clean, well-oxygenated water.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Ecosystem health can be monitored by observing how different species react to changes in their environment.
Some species are highly sensitive to pollution, habitat loss, or climate change, and can act as early warning systems for ecological damage.

Step 2: Detailed Explanation:
Let us define the ecological terms listed in the options:
- Keystone species:
A species that has a disproportionately large effect on its community relative to its abundance (e.g., sea otters, sea stars).
Their removal can cause major changes across the entire food web.
- Native species:
A species that occurs naturally in a specific region or ecosystem without human intervention.
- Specialist species:
A species with a narrow niche that can only survive in a specific habitat or on a specific diet (e.g., pandas feeding only on bamboo).
- Indicator species:
A species whose presence, absence, or population health reflects the environmental conditions of its habitat.
Because they are highly sensitive to environmental shifts, changes in their population or behavior provide an early warning of pollution, chemical contamination, or climate changes.
Common examples include:
- Lichens: Used to monitor air quality.
- Stonefly larvae: Used to monitor dissolved oxygen levels in freshwater streams.
- Amphibians: Highly sensitive to both water and land pollution due to their permeable skin.

Step 3: Final Answer:
Indicator species serve as early warnings of environmental damage.
Thus, the correct choice is (D).