A recent study supported by the Army Corp of Engineers found that barged
fish are more stressed over time than run-of-river fish based on levels
of cortisol present in the fish.
Yet, there are only a few differences in behavior between barged and
run-of-river fish when they are in the Columbia River estuary.
"All fish were stressed to some point, but fish collected at Lower
Granite Dam were more stressed than run-of-river fish," said Tom Stahl,
Oregon Cooperative Fish …