According to Save Our Wild Salmon, a coalition of environmental groups and
commercial and sport fishing associations, dams alone are responsible for the
loss of 92 percent of salmon headed out to sea and of up to 25 percent on
their way back upstream. "Fish are gone entirely from almost 40 percent
of their historic rivers," says Dietrich, who adds that most of the
remaining fish are at risk, too, qualifying for full protection under the
Endangered Species Act. Quite simply, the fish just cannot swim past the dams.