THE SHENANDOAH-NATIONAL-PARK - FISH IN SENSITIVE HABITATS (SNP-FISH) PROJECT - AN INTEGRATED ASSESSMENT OF FISH COMMUNITY RESPONSES TO STREAM ACIDIFICATION

The ''Shenandoah National Park: Fish in Sensitive Habitats'' (SNP:FISH ) project is a response to declining pH and acid neutralizing capacity in Shenandoah National Park (SNP) streams. SNP receives more atmosphe ric sulfate than any other USA national park, and pH had decreased to the point where early negative effects on fish were expected. SNP prov ides the opportunity to study the early stages of acidification effect s on fish. Three different classes of geological formations yield stre ams with low-ANC (0 mu Eq/L), intermediate-ANC (60-100 mu Eq/L) or hig h-ANC (150-200 mu Pq/L) waters in SNP. This allows a comparison of res ponses across a water quality gradient in a small geographic area rece iving similar deposition. Both chronic and episodic acidification occu r in SNP streams. Biological effects are apparent in fish species rich ness, population density, condition factor, age, size, and bioassay su rvival. A primary project objective was to provide the necessary data for development and testing models for forecasting changes in fish com munities resulting from changes in stream chemistry. Monitored variabl es include several which are predictive of acidification effects on SN P fish communities.