1 Introduction A high-quality supply of water is critical to the well-being of both human and natural systems, yet these resources face a number of threats. Freshwater makes up less than 1% of the surface water on the planet, yet is critical to 7%–12% of all species, including one third of all vertebrates; many primarily terrestrial or marine species depend on these resources for some part of their life cycle (Abramovitz & Peterson, 1996; Balian et al., 2010; Dudgeon et al., 2006).
