Updated Extinction Study Shows Time is Quickly Running out for the Snake River Salmon
4/25/2001 — — Wild salmon projected to reach functional extinction in 15 years
Alan Moore, Western Communications Coordinator, Trout Unlimited: 503-827-5700
April 25, 2001…Portland, OR…A detailed study of the extinction timeline of the Snake River salmon has found that Snake River spring/summer chinook could be functionally extinct in 2016 unless conditions change.
The study, which was undertaken by Drs. Gretchen Oosterhout and Philip Mundy, looked at seven index stocks of spring/summer chinook salmon, stocks the federal and state fishery agencies have been monitoring for over 40 years and using as indicators of the health of the Snake River spring/summer chinook. It concluded that expected extinction date for the salmon ranged from 2007 for the stocks facing the greatest risk of extinction to 2033 for the stocks facing the lowest risk, with 2016 being the median date for functional extinction.
Functional extinction, a term used by conservation biologists, occurs when a population of a species declines to such a degree that they it becomes virtually impossible for the population to survive, let alone recover. At low numbers inbreeding starts to occur and individual animals have difficulty finding mates.
The findings of this study make clear that in spite of the recent high runs of salmon, the future of the Snake River salmon is dim and is in fact fading with every passing year, said Jeff Curtis, Western Conservation Director for Trout Unlimited, the organization that commissioned the study.
Trout Unlimited had commissioned a previous study that was released in 1999 that explored the probable extinction timeline for the wild Snake River salmon. That study, which was completed by Dr. Mundy and became known as the “Doomsday Clock,” set the median functional extinction date for the salmon at 2017.
Mundy, a widely-respected Pacific Northwest fisheries biologist, and Oosterhout, a noted decision systems analyst from Oregon, were commissioned to update the study, using additional data and more refined techniques to expand the extinction model, known as Year Class Strength or YCS, used in the new “Doomsday Clock” study. In spite of the additional data and including making the model stochastic, which allows the calculations to take into account the variability of nature, the extinction date was nearly identical to the simpler model used in the 1999 study.
The YCS model, unlike other salmon population tracking models that have looked at salmon populations as a whole, analyzes each individual year class of wild Snake River salmon, a concept developed by Dr. Mundy when he noted that there were patterns of strong and weak runs over time. For example, weak runs in 1994 were followed by a very weak run in 1999; stronger runs in 1996 are being replicated by the stronger runs in 2001.
The value of the YCS model was proven by Dr. Oosterhout when she ran a comparison of the YCS model and models used by NMFS Cumulative Risk Initiative (CRI) as the basis for the extinction analysis in the recently released biological opinion. Dr. Oosterhout conducted an experiment using twenty years of data. She ran the models using the first ten years of data to see how they projected the second ten years. The NMFS models projected returns considerably higher, by orders of magnitude, than actual returns. The YCS model fit the data much better, even predicting an upswing in 2000 and 2001.
The overly optimistic projections of the CRI model are demonstrated in the CRI’s projections of the expected timeframe for extinction for Sulphur Creek spring chinook salmon — one of the seven indicator stocks — at 317.4 years. Actual spawning data tell a different story with zero Sulpher Creek fish returning to their spawning streams in 1999. The YCS model found the Sulphur Creek spring chinook salmon to be the third most threatened of the seven indicator stocks with 2010 being its projected date of functional extinction.
Curtis said one of the reasons Trout Unlimited commissioned the study was to provide the public and decision-makers with credible analyses in order to help them make decisions pertaining to the survival of the wild Snake River salmon.
“No matter how fervently the federal government or backers of expensive techno-fixes like barging fish attempt to put a positive spin on it, there is no getting around the likelihood that the wild Snake River salmon are going to go extinct in our lifetime if something doesn’t happen soon to turn around their decline,” Curtis said.
He added that what makes the study’s findings especially troubling is that this years smaller than normal snow-pack, combined with the abandonment by the federal government of even the modest recovery provisions in the 2000 Biological Opinion, may result in the virtual elimination of a generation run of salmon. That loss could bring the date of extinction even closer.
As we and others have said all along, the survival of wild Snake River salmon is in jeopardy. While everyone agrees we have an energy emergency, the emergency for the salmon is even more serious, he said.
Trout Unlimited is North Americas leading coldwater conservation organization, dedicated to the conservation, protection and restoration trout and salmon fisheries and their watersheds. The organization has more than 130,000 members in 472 chapters in North America, including 8,000 members in the Pacific Northwest.