Description
Flow alteration and urban development have been associ-ated with stream ecosystem degradation in flowing waters as measured through fish communities (Karr and Chu, 1999; Freeman and Marcinek, 2006; Zorn, 2008; Poff and others, 2010) and macroinvertebrate communities (Coles and others, 2004; Konrad and others, 2008; Kennen and others, 2009). Streamflow is one of many factors that influence the abun-dance and distribution of fish, and has been called the master variable because it influences habitat availability, channel geomorphology, and other factors that also influence habitat quality such as water quality and water temperature (Wilding and Poff, 2008; Poff and Zimmerman, 2010). The likelihood that flow alteration and urbanization will degrade aquatic com-munities is generally acknowledged by the scientific commu-nity and by water managers (Poff and Zimmerman, 2010), but the response of aquatic communities to flow alteration relative to the influence of physical basin and land-cover (environmen-tal) characteristics and other anthropogenic factors is poorly understood.
