What is a bioindicator?

Bioindicators are organisms (plants, microorganisms, animals, etc.) used to assess or observe the ecosystem’s health. Changes in their diversity or population can reflect the existence or increase of pollution or any other factor that can harm the balance of the natural ecosystem.

Lemna sp., a genus of aquatic plants, is a common bioindicator used to test the possible negative effects of a new product (fertilizer or phytochemicals) before it gets certified and released on the market.

Honeybees are also bioindicators, as their population and activity can be used to assess the ecology profile of a certain region. Another example of a bioindicator is lichens. These plants, which live on surfaces such as trees, rocks, or soil, are very sensitive to toxins in the air. This is because they obtain their nutrients mostly from the air. We can tell our forests have clean air by the amount and types of lichens on the trees. In the photo, we can see Hypnum cupressiforme with capsules (sporangium) containing spores. It is also a bioindicator for environmental pollution.

Reference

https://www.sciencelearn.org.nz/resources/1538-bioindicators