Diversity-Production Relationships of Appalachian Stream Fish Assemblages

Ecologists have long recognized the importance of relationships between species diversity and production; nonetheless, diversity-production relationships have not been extensively explored for freshwater fish assemblages. Stream ecosystems and fisheries are a valuable resource for cultures and economies, thus diversity-production relationships for fish assemblages should be identified for use in fisheries management. The purposes of this study were to 1) evaluate the diversity-production hypothesis in stream fish assemblages across the Appalachian Mountains; 2) examine how diversity-production relationships may vary across stream thermal classes; and 3) compare standardized diversity-production relationships of fish assemblages to published relationships of other taxonomic groups. Annual fish assemblage production varied from 0.15 to 6.79 g m^-2 yr^-1. Fish assemblage production was significantly and positively related to species richness (R²=0.38, P=0.001), Shannon’s Diversity Index (R²= 0.23, P=0.02), and community evenness alone (R²= 0.22, P=0.01). Furthermore, these relationships increased in strength and significance after accounting for covariates of productivity (e.g., temperature and water chemistry, R²=0.54, P=0.0004, R²=0.49, P=0.001, and R²=0.49, P=0.001, respectively). The diversity-production relationship for stream fish assemblages was among the strongest reported for a range of taxonomic groups. Management of freshwater fisheries for production may be more closely linked to conservation of fish diversity than previously thought.