An indicator species (or bioindicator) is an organism whose presence, absence, or population size reflects the overall health and specific environmental conditions of an ecosystem.
- They act as early warning systems, alerting ecologists to pollution, habitat degradation, or climate change long before the broader ecosystem collapses.
- They react quickly to minor changes in environmental variables (like pH, temperature, or toxicity).
- They survive only within a limited set of parameters.
Example
- Pelicans for wetlands
- Lichens for air pollution
- Gangetic River Dolphin for the Ganga-Brahmaputra river system.
Source: Down To Earth