SUNY Brockport professor helps uncover link between fish diets and salmon health crisis

A major study published in the academic journal Proceedings of the National Academy of Sciences (PNAS) uncovered alarming evidence about the impacts of changing ocean diets on salmon health, focusing on thiamine (vitamin B1) deficiency in Chinook salmon populations in California—a similar issue the Great Lakes region has faced for decades.

“These are the same issues we’ve been seeing in the Great Lakes since the 1960s,” said Dr. Jacques Rinchard. “California’s seeing it now with endangered salmon, and our decades of data helped confirm what’s happening there.”

When researchers from the National Oceanic and Atmospheric Administration (NOAA) Fisheries and other universities identified the issue in 2020, Rinchard was brought on as a collaborator due to his years of experience monitoring native lake trout health across all five Great Lakes, the Finger Lakes, and Lake Champlain, with support from the U.S. Geological Survey.

Warmer waters and a shift in prey—particularly a diet dominated by anchovies—have been linked to poor fish health, developmental issues, and reduced survival rates in California. Anchovies contain thiaminase, an enzyme that breaks down thiamine, and as salmon increasingly rely on them for food, they pass on the deficiency to their offspring. Embryos often fail to develop properly, leading to lethargy, swimming problems, and death.

“In the wild, this is difficult to treat,” Rinchard said. “Instead, we have hatcheries where we can raise eggs for the stocking program, and there, we can treat the eggs and embryos with thiamine.”

Jarrod Ludwig, a former graduate student from SUNY Brockport and a fish biologist at the NYS Department of Environmental Conservation, was working to find another way to address the problem.

Ludwig traveled to California to conduct research with NOAA for his master’s thesis, analyzing regional diet differences in California salmon eggs using fatty acid analyses and their connection to thiamine levels.

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