Trait Composition of Fish Assemblages across Hydrologic Regimes

Hydrology is a primary driver determining the physical and chemical characteristics of streams. Because hydrology controls many important habitat attributes, stream fish traits reflect hydrologic conditions. Climate change will likely have significant effects on natural flow patterns, as well as exacerbate flow alterations due to anthropogenic use. Understanding how stream fish community structure relates to hydrology is crucial for predicting how fish communities may respond to climate change and increased anthropogenic flow alteration. This study utilizes a trait based approach to determine how fish communities are structured across hydrologic gradients at a management level spatial scale. The relationships between individual functional fish traits, trait syndromes, individual hydrologic metrics, and hydrologic regimes were determined using a combination of RLQ and 4^th corner analysis for over 500 streams in Arkansas. This study provides not only regional patterns in fish community structure across hydrologic regimes, but also identifies traits and hydrologic metrics that are important for predicting fish community responses to flow alteration.