INTEGRATING BIOLOGICAL MONITORING DATA FROM DIVERSE SOURCES: CHALLENGES IN DATABASE AND INDEX DEVELOPMENT FOR POTOMAC NONTIDAL RIVERS AND STREAMS.

L.E. Astin. Interstate Commission on the Potomac River Basin, 6110 Executive Blvd., Suite 300, Rockville, MD, 20852

Research on the nontidal Potomac is hampered by data in varied forms that cannot easily be compared. The objective of the Interstate Commission on the Potomac River Basin (ICPRB) Basinwide Assessments program is to improve understanding of the biotic integrity of the Potomac watershed by combining monitoring data from member jurisdictions (Maryland, Pennsylvania, Virginia, West Virginia, and the District of Columbia) with available contextual information. However, "[t]he ability to combine unlike datasets has historically been a problem for scientific investigations" (Barbour et al. 1999). While states' results cannot be compared directly, most apply a similar analysis approach requiring a stream classification framework to partition variability into relatively homogenous groups. ICPRB is adapting this framework to resolve differences across classification schemes. Raw data were assembled in a Microsoft Access database. Consistent criteria from state habitat and water quality assessments were selected and normalized to a common scale. Classification schemes using select landscape features and stressors were evaluated. Sites classified under these criteria were used to define ecological expectations for each stratum. We highlight the challenges encountered in developing the database as well as adapting the framework for translating diverse data into an integrated assessment of biological condition for the Potomac watershed.