A 2020 study of literature by David Welch and his team at Kintama Research has been debunked by scientists at the independent, federally-funded Fish Passage Center.
The Welch paper analyzed Chinook salmon population data from across the Pacific coast of the U.S. and Canada, concluding that “most of the salmon conservation problem is determined in the ocean by common processes.” Welch’s flawed analysis points to poor conditions in the Pacific ocean as the root cause of the Chinook salmon’s sharp decline.
The Bonneville Power Administration (BPA) funded Welch’s research, one of several papers that have deflected blame for fish declines away from the federal hydropower system, which BPA operates. BPA support of this type of research stands in stark contrast to peer-reviewed, scientifically rigorous studies that most fish biologists endorse. Reputable studies have concluded that the biggest factor in the continued decline of Snake River salmon and steelhead is the hydroelectric system of dams.
In reviewing the paper, the Fish Passage Center laid bare the Welch team’s faulty analysis and assumptions, and concludes that “Welch et al. (2020) is technically flawed. Therefore their contentions…are not supported by the considerable body of available scientific information.”
Here are some highlights from the Fish Passage Center’s review:
“Not even the best ocean conditions can resurrect a dead fish.” The Welch team’s focus on ocean conditions is misplaced. Multiple studies have shown that fish survival is largely dependent on their downstream migration corridor, which has been made dangerous and exhausting by dams and their reservoirs. Whether ocean conditions are bad or good, it’s critical to improve survival in freshwater so that as many juvenile fish reach the ocean in good condition as possible.
“Wild spring Chinook stocks in the Columbia River Basin that experience less hydrosystem impacts (e.g. John Day River and Yakima River) have much higher survival than stocks that experience greater hydrosystem impacts (Snake River, Upper Columbia River).” In a reanalysis of Welch’s data, the reviewers found that 11 of the stocks had significantly declined since the 1960s. Of the 11, four are Snake River and Upper Columbia stocks, which must pass eight dams in their upstream migration. The Fish Passage Center also showed, again using Welch’s own data, that survival for Snake River stocks is significantly lower than nearly every other stock in the study. This clearly points to Snake River fish being pushed toward extinction by hydroelectric dams.
The Welch team made no effort to ensure the data it was analyzing, which came from multiple sources and was collected in multiple ways, actually made sense to compare. Salmon populations, as they are measured in California, cannot be readily compared to the same data from the Snake River. “The authors fail to meet the most important requirements of a synthesis or meta-analysis…Their approach results in an ‘apples to oranges’ comparison at best, and a misrepresentation of the data utilized and erroneous conclusions at worst.”
As the Fish Passage Center, U.S. Army Corps of Engineers, NOAA Fisheries, state and tribal agencies, and many independent scientists have previously concluded many times over, four dams on the lower Snake River continue to hinder salmon and steelhead, impeding their recovery. Breaching these dams would bring immediate results for Idaho’s fish, easing their journey to the ocean and their migration home.