Pteronarcys californica, or the giant stonefly, is an important shredder in North American streams. Several populations in Montana may be imperiled because they live in streams with decreasing flow.
A really nice little study conducted in our lab by undergrad James Frakes (now a grad student) on how flow affects tolerance to heat stress and hypoxia in a stonefly. James found that when giant stoneflies (Pteronarcys californica) are exposed to heat, they can withstand higher temperatures when the water is flowing compared to when it is still. Similarly, they can handle lower oxygen concentrations (hypoxia) in flowing versus still water. These findings have implications for aquatic insect vulnerability to climate change. Insects living in streams where flows are decreasing may be much more vulnerable than previously thought.