Estimates of spring and summer chinook juveniles that made it through
the Snake River and Columbia River hydroelectric projects from the mid-1960s
to today clearly show a downward trend in juvenile survival as dams were
added to the river.
More recently, however, the numbers shows a reverse in that trend as
improvements were made at dams to lower the stress on fish.
Preliminary PIT-tag data for 1993 through 1999 show that juvenile survival
is as high or higher now than it was before …
