NOAA 99-R120
Contact: Brian Gorman


In a draft scientific analysis released today, the National Marine Fisheries Service offered a biological evaluation of options that could help in the recovery of threatened and endangered species of salmon along the Snake River. Although the scientific study suggests that under the widest set of assumptions, the drawdown or breaching of the four federal Snake River dams may be the most "risk-averse" alternative, the report finds that there are significant uncertainties associated with these projections.

"The task of any scientific report of this nature is to evaluate, as clearly as possible, the effects of options available to policy makers," said Terry Garcia, U.S. Commerce Department's assistant secretary for oceans and atmosphere."This draft options report does just that, no more, no less.It doesn't recommend a preferred course of action nor does it reflect a policy decision.It remains for the region, the Administration and the Congress to consider this and other factors before any policy determination is made about this issue."

This draft of NMFS options report, "An Assessment of Lower Snake River Hydrosystem Alternatives on Survival and Recovery of Snake River Salmonids," analyzes the likely biological effects of the two basic options for the Snake River dams: drawdown or breaching of the lower Snake to its natural river level by removing the earthworks adjacent to the dams, or leaving the dams intact and continuing the transport of juvenile fish around them by barging or trucking.Under certain scenarios, there is little or no improvement from dam breaching.The report acknowledges that further research into the biological consequences of transportation can greatly reduce some uncertainties, but it also cautions that delay itself could pose additional risks to the salmon.

"This draft report is our best scientific estimate, at this time, of the biological effects of these options on the salmon and steelhead populations," said William Stelle Jr., head of the fisheries service's Northwest regional office in Seattle."Other information must be considered, including effects on other fish and wildlife species, and the economic and social consequences of the options on the region."

The NMFS options report is being sent to the U.S. Army Corps of Engineers today for inclusion in the Corps' larger study of Snake River dam breaching.That study will contain a further analysis of the social and economic effects of the options, in addition to this biological analysis.The entire Corps document will be released in draft form for public hearing and comment later this year.

This summer, the National Marine Fisheries Service will seek a review of its options report by the Independent Scientific Advisory Board, an independent panel established by the fisheries service and the Northwest Power Planning Council in 1996.The report will also be provided to members of the PATH modeling group for comment.PATH, which is an acronym for Plan for Analyzing and Testing Hypotheses, is a group of 25 regional biologists, engineers and statisticians who provided the original analysis.

The options study looked at many of the hundreds of factors in the complex life cycles of the four populations of salmon in the Snake River currently protected by the federal Endangered Species Act. The listed fish are spring/summer chinook, fall chinook, sockeye salmon and steelhead.

The fisheries service research scientists who worked on the report said at its heart are several life-cycle computer models of salmon, from the time the fish lay their eggs through their down-river migration, growth in the ocean and eventual return to spawn.

Dr. Usha Varanasi, head of Seattle's Northwest Fisheries Science Center which conducted the study, added that, "Threats to salmon survival, as well as opportunities for recovery, occur at every stage of the salmon life cycle.Our job was to make predictions, based on sound science, about what those threats and opportunities are and how they can affect salmon recovery."

Further information, including a map, fact sheets and the report itself, is available on the Northwest Region's Web site at