fish and other freshwater organisms from polluted waterways, for example, whose death or unusual behavior may indicate the presence of hazardous pollutants that have escaped other detection methods. [fn]Source: (IISD 2005) from IISD website; http://www.iisd.org/sd/glossary.asp (updated: Aug 2005)[/fn]. Organism used to establish the presence of an environmental change through its known reaction to specific environmental phenomena. The change may involve the population of the organism, its growth, mortality, reproduction rate, structure, phenology, chemical composition or other parameter. [fn]Source:(EFI 2002) from European Forest Institute, Internal Report No. 6, 2002 "Compliation of Forestry Terms and Definitions" by Schuck, Paivinen, Hytonen, and Pajari.[/fn]