Everything you need to know about living organisms that are key to our survival
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15:34 min
What exactly is a bioindicator?
An organism whose presence, absence, or behaviour reflects environmental conditions — signalling pollution or ecological change.
Why use bioindicators instead of measuring pollution directly?
They're highly sensitive to small environmental changes, often flagging problems early. They're also local, abundant, and easy to monitor.
Which organisms are commonly used as bioindicators?
Amphibians, lichens and mosses, honeybees, earthworms, bivalves like mussels and clams, and plankton. Nearly 70% of indicator species are invertebrates.
How do bioindicators show that something is wrong?
Through changes in reproduction, numbers, behaviour, or physical abnormalities. Bivalves, for example, accumulate heavy metals in their tissue while filtering water.
What threatens bioindicator species themselves?
Pollution, habitat loss, invasive species, and climate change — especially shifts in temperature and rainfall that disrupt life cycles.
About the Authors
Phalguni Ranjan
Drawing on her previous experience with outreach creatives, marine research, and communications to guide her, Phalguni uses words, art, and visuals to help people connect with wildlife and nature.
