WATER QUALITY--Measurement and Use of Diversity Indices for Biological Samples 

In Reply Refer To:                           April 16, 1985
WGS-Mail Stop 412



QUALITY OF WATER BRANCH TECHNICAL MEMORANDUM NO. 85.10

Subject:  WATER QUALITY--Measurement and Use of Diversity 
                         Indices for Biological Samples

Enclosed for your information is a restatement of Quality of 
Water Branch Technical Memorandum No. 82.07.  Please note 
especially equation 4, (page 5) for the calculation of Hmax.  
This equation was in error in memorandum 82.07 and has now 
been corrected.  We thank Jurate Landwehr, Northeastern 
Region Research, for bringing this problem to our attention.

Changes in biological communities caused by natural or 
anthropogenic stress are often of interest in water-quality 
studies.  Diversity indices have been among the most widely 
used methods for identifying changes in aquatic community 
structure.  The use of indices to summarize large amounts of 
species-abundance information is still undergoing 
development, but the content of Quality of Water Branch 
Technical Memorandum No. 82.07 (February 10, 1982) remains 
relevant.  A recent review (Washington, H. G., 1984, 
Diversity, biotic and similarity indices:  A review with 
special relevance to aquatic ecosystems: Water Research, 
v. 18, no. 6, p. 653-694) provides a state-of-the-art 
discussion of the subject; a number of different diversity 
indices as well as biotic and similarity indices are examined 
for their applicability to aquatic ecosystems.




                      David A. Rickert
                      Acting Chief, Quality of Water Branch

Attachment

WRD Distribution: A, B, FO-LS, PO

This memorandum supersedes Quality of Water Branch Technical 
Memorandum No. 82.07