Doomsday clock ticks for Snake River salmon

Updated study projects functional extinction in 15 years

ESPN Outdoors news services

Portland, Ore — A detailed study of the extinction timeline for Snake River salmon has found that spring/summer chinook could be functionally extinct in 2016 unless conditions change, reports a Trout Unlimited press release.

The study, which was undertaken by doctors 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 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.

“ The future of the Snake River salmon is dim and is in fact fading with every passing year ”
— Jeff Curtis, Trout Unlimited

Functional extinction, a term used by conservation biologists, occurs when a population of a species declines to such a degree that it becomes virtually impossible for the population to survive, let alone recover. At such low numbers inbreeding starts to occur.

"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, and 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 YCS model proved accurate when Dr. Oosterhout 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 tells a different story with zero Sulphur 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.