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NW Fishletter #375 November 6, 2017
 2017 Columbia Salmon Returns Off, Prospects Poor for Near Term
This year's Columbia and Snake river salmon and steelhead returns are down, and fish have not come back in the numbers forecast.
Although the 2017 return estimates are not yet final, this is the second year in a row that most stocks have fallen below preseason predictions.
Even the returns of fall Chinook, the Columbia's most abundant salmonid, have been off. Fall Chinook passing Bonneville Dam in 2017 have numbered about 314,000, below the forecast of about 500,000 fish. The count to date is some 61 percent of the 10-year average.
At Lower Granite Dam, the fall Chinook adult count of 26,000 is about 76 percent of the 10-year average.
This year's Bonneville Dam adult steelhead count of 117,000 is about 36 percent of the 10-year average. The unclipped or wild component of the run is now at 34,000--31 percent of the 10-year average.
The 2017 Lower Granite steelhead count of 72,000 is some 50 percent of the 10-year average. The Lower Granite unclipped steelhead count of nearly 14,000 is about 36 percent of the 10-year average.
At Willamette Falls, the 2017 count for steelhead was 2,800. This year's steelhead count is about 12 percent of the 10-year average count.
Hatchery fish like this Chinook make harvests possible. Credit: ODFW
An exception this year is Snake River coho passing Lower Granite Dam. At 7,800, the 2017 Snake River coho count represents nearly twice the 10-year average.
This is notable because several decades ago, coho were extinct in the Snake River, none having crossed Lower Granite Dam between 1987 and 1997. In 1995, the Nez Perce started a successful hatchery program to bring them back to the Clearwater River, a Snake River tributary where they were once abundant.
However, optimism about Snake River coho has to be tempered by the fact that in 2014, some 14,500 coho returned to the Clearwater, not quite twice this year's number.
While the cumulative coho count of 71,200 at Bonneville Dam to date is much better than the 2016 count, it is only about 66 percent of the 10-year average.
Pacific lamprey were also a notable exception for the basin's sea-going species in 2017. Once ubiquitous in the Columbia and Snake rivers, the lamprey did very well this year, besting the 10-year averages at Bonneville and Lower Granite dams and in the upper Columbia at Priest Rapids and Rocky Reach dams. Over 82,000 lamprey have been counted at Bonneville Dam so far this year.
In the next few years and maybe longer, the problems for Columbia Basin salmon and steelhead are likely to continue.
NOAA Fisheries research surveys in June of 2017 showed the fewest juvenile salmon in waters off the Pacific Northwest coast in 20 years of research. The results strongly suggest that the current ocean environment has not been conducive to the survival of young salmon.
A recent memorandum by the Northwest Fisheries Science Center, a NOAA affiliate, reported the survey counts and said ocean indicators "have turned largely negative for Columbia River salmon."
Warmer sea temperatures appear to be changing the ocean ecology to the detriment of salmon.
Another research study by Pacific States Marine Fisheries Commission, Oregon State University and the Northwest Fisheries Science Center says that a warmer ocean is shifting fish species northward, and some species that spawned in the summer are spawning year round.
The new research found that anchovy and sardine are present in Northwest waters earlier in the year and closer to shore than previously observed.
An article about the research by NOAA Fisheries' writer Michael Milstein said that anchovies and sardines may be an additional food source for young salmon, but could also contribute to yet-unknown alterations in the food web that would increase competition among fish species.
Alterations in predator-prey relationships could also prove hazardous to young salmon.
"The findings underscore the vast influence the ocean exerts over salmon survival and the importance of providing salmon with healthy freshwater habitat so they can weather poor ocean conditions and take advantage of favorable conditions when they return," the Northwest Fisheries Science Center memo said.
Oregon, Washington and the Columbia River Inter-Tribal Fish Commission usually make their 2018 salmon and steelhead forecasts in late January. The science center won't make its 2018 prognostications until March. -Laura Berg
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