For instance, Weber's team have discovered that discharges from the powerhouse, thought to dilute gas concentrations, are actually contributing to the problem at some dams. Salmon populations have plummeted over the last century. Population counts of some species, such as the Redfish Lake sockeyes, have fallen into the single digits. So uncertain is the salmon's future in some river stretches that in 1998 the U.S. Endangered Species Act listed runs for 9 of 10 major species as threatened or endangered. Juvenile mortality is only part of the problem.
Additional causes are as complicated and far-reaching as climate change and urban sprawl.
River3D is also fast. Because all river construction in the Columbia Basin halts during the spring and summer runs, engineering teams have only six to nine months in which to evaluate data, design, and test new designs, then implement the most promising. This summer the team is testing a fish behavioral component they've added to the software. They have integrated a particle tracer that replicates the behavior of fish in response to flow conditions and other stimuli. Programmers in NCSA's computational fluid dynamics group are further modifying the code to be massively parallel so it will work in realtime on the SGI Origin2000 system.