bioindicator

This term is primarily used in scientific, ecological, and environmental contexts. It describes a biological proxy used to infer the state of an environment without needing direct chemical analysis of the medium. The connotation is objective and analytical, typically appearing in research papers, environmental impact reports, and academic textbooks.

While the word is a technical noun, it is used to describe a wide range of entities from single-celled microorganisms to complex animal species. It is distinct from a "biomarker," which typically refers to a molecular or cellular change within a single organism, whereas a bioindicator often refers to the status of a whole population or species within an ecosystem.