HISTORICAL CHANGES IN FISH ASSEMBLAGE COMPOSITION FOLLOWING WATER QUALITY IMPROVEMENT IN THE MAINSTEM TRINITY RIVER OF TEXAS

摘要: The Clean Water Act of 1972 is credited with improving water quality across the USA, although few long-term studies tracking hydrologic, chemical, and biological responses to cleanup efforts exist. Trinity River Texas was plagued by poor for more than a century before passage legislation reduce point source pollution from Dallas–Fort Worth (DFW) Metroplex. We tracked changes in components flow regime; concentrations ammonia, nitrate, phosphorus, biochemical oxygen demand (BOD); fish assemblage composition three mainstem reaches during 40-year period (1968–2008) following implementation large-scale initiative. Results suggest little change regime such as magnitude, timing, rate among 1968–2008. Concentrations parameters declined through time greater distance DFW, including lowest reach downstream reservoir (Lake Livingston). Fish shifts correlated attenuated nutrient BOD concentrations, species richness generally increased all reaches. Native intolerant fishes consistently reaches, lentic non-native also Lake Livingston. Our findings revitalization associated reduced DFW (even distant reaches) illustrate potential confounding factors stream impoundment continued deposition that likely preclude complete recovery. Copyright © 2014 John Wiley & Sons, Ltd.