Inadequacy of diversity indices in discerning metal mine drainage effects on a stream invertebrate community

✍ Scribed by James W. Chadwick; Steven P. Canton

• Book ID: 104650330
• Publisher: Springer Netherlands
• Year: 1984
• Tongue: English
• Weight: 367 KB
• Volume: 22
• Category: Article
• ISSN: 0049-6979
• DOI: 10.1007/bf00163102

✦ Synopsis

The benthic invertebrates of the Dolores River in southwest Colorado were sampled during three seasons in an area of historic mine drainage. Benthic density exhibited significantly lower values below the mine drainage. However, the number of species did not decrease significantly, indicating that the effect of the mine drainage was primarily non-selective (i.e. favoring no one taxon). This pattern was seasonal with the least effects evident in summer and the greatest effects found in spring. Diversity indices used to assess the effects of this stress on the invertebrate community were Margalet's, Simpson's, Shannon-Weaver's, Brillouin's, and the Biotic Condition Index. None of the indices tested adequately responded to a decreasing trend in the benthic density when number of species remained constant. The indices did respond to a combination of low density and number of species or to the predominant representation by one species. The Biotic Condition Index actually increased at the stations with the lowest density and number of species. Diversity indices appear to be inadequate in assessing a non-selective stress.