The Ice Harbor Dam on the Snake River near Burbank, Wash., is shown in 1999. Justice Department made its rebuttal argument Wednesday. (Associated Press file photo)

PORTLAND, Ore. - Conservationists and the federal government argued in court this week over whether the federal government is responsible for the threatened and endangered salmon that die making their way past hydroelectric dams on the Columbia and Snake rivers.
   A coalition of environmentalists, sports anglers and American Indian tribes argued that the latest federal program for operating the dams under the Endangered Species Act treats the man-made structures as part of the landscape and fails to take responsibility for irreparable harm to the fish.
   In their rebuttal Wednesday in U.S. District Court in Portland, the Justice Department argued that the federal agencies that control the 14 dams dissecting the Columbia and Snake Rivers cannot be held responsible for the existence of the dams, which predate the passage of the Endangered Species Act.
   They   can only be held responsible for the extra mortality caused by how the dams are operated, not the mortality based on the existence of the dams, said attorney Fred Disheroon, representing NOAA Fisheries, the federal agency responsible for restoring salmon runs in danger of extinction. ''The statute applies to those things you can stop. You cannot stop operating the hydrosystem. You have to operate it in some way,'' he said.
   At the end of the nearly eight-hour long hearing, U.S. District Judge James Redden said he intended to issue his decision in early May, adding: ''It is not an easy decision to make - and I hope I make the right one.''
   Under the Endangered Species Act, NOAA Fisheries must decide whether the federally operated dams jeopardize the survival of 12 threatened and endangered salmon runs, and if they do, propose ways to overcome the harm.   The review is known as a biological opinion.
   In May 2003, Redden ruled that the biological opinion issued in 2000 was illegal because the federal government could not guarantee that habitat enhancements and upgrades to hatchery and dam operations would be done.
   The latest biological opinion set a new course for salmon recovery by taking the stand that the dams are part of the ecosystem and cannot be removed.