This report documents research undertaken to determine if the theoretical promise of genetic diversity as an ecological indicator is realized in real-world applications. Results of two case studies confirm that genetic diversity is a useful indicator of environmental condition. The first case study incorporated the genetic diversity indicator in a larger Regional Environmental Monitoring and Assessment Program study of the Eastern Cornbelt Plains Ecoregion, done in collaboration with US EPA Region 5 and Ohio EPA. Genetic diversity of a small cyprinid minnow, the central stoneroller (Campostoma anomalum), was measured at 91 sites in nine watersheds using the RAPD (random amplified polymorphic DNA) fingerprinting technique. Although the RAPD technique was chosen primarily for ease of technology transfer, experiences with the technique suggested that it might not be robust to the normal variations in equipment and technical skills that exist among different laboratories. Nonetheless, the genetic diversity data obtained proved highly informative. The second case study examined the genetic diversity indicator applied to populations of the creek chub (Semotilus atromaculatus) in a small region of western Pennsylvania and West Virginia underlain by coalbearing geology and for which the history of coal mining operations is known. Samples of between 9 and 28 creek chubs were collected from 10 sites within 4 watersheds. Two molecular methods were used: the amplified fragment length polymorphism (AFLP) fingerprinting technique was used to assess diversity in the nuclear genome, while a portion of the mitochondrial genome was assessed using DNA sequencing. These two case studies clearly demonstrate that genetic diversity can serve as an indicator of environmental condition. They also provided the practical experience upon which recommendations for future implementation are based.

"EPA/600/R-03/056." "September 2002." Includes bibliographical references (pages 65-70). CD-ROM.