Rivers need water — a fact that may seem ridiculously obvious, but in times of increasing water development, drought and climate change, the quantity of natural streamflow that remains in river channels is coming into question, especially in the Colorado River basin. Newly published research from Utah State University poses a tough question in these days of falling reservoir levels and high-stakes urban development: whether the continued development of rivers for water supply can be balanced with fish conservation.
Historically, the Colorado River basin has been highly dynamic with a wide range of streamflow, river temperatures and large sediment loads. Native fish evolved through periods of wet and dry cycles. But water-supply development has depleted the flow of many rivers in the Upper and Lower Colorado River basins, and today’s river habitats are increasingly decoupled from the natural cycle of spring snowmelt, monsoon-season floods and intervening low flows in favor of development and for stocking nonnative sports fish.
The health and recovery of native fish species now depends largely on the public’s willingness to protect rivers that retain some semblance of a natural flow regime as freshwater conservation areas, say authors Casey Pennock, Phaedra Budy, Wally Macfarlane and Jack Schmidt of the Watershed Sciences Department in the S. J. and Jessie E. Quinney College of Natural Resources and colleagues.
Read more at S.J. & Jessie E. Quinney College of Natural Resources, Utah State University
Image: Threatened and endangered native fish of the Colorado River need access to the most basic of resources for recovery — adequate natural streamflow, according to new research. (Photo courtesy Nate Cathcart)