Sometimes stories cross my desk that don't fall into my typical coverage, but are just too interesting to pass up.
Take this one, for instance.
What does it take to make a fine California wine? Grapes, water, sunshine, the skilled hand of a master vintner – and, now for the punch line – a few thousand dead fish.
A few thousand dead Chinook salmon, to be specific, according to new research that shows that the salmon that die naturally in California's Mokelumne and Calaveras rivers contribute significantly to the growth -- and likely the quality -- of wine grapes raised nearby. I suppose if it’s true there, then it must be true for the salmon that run up the Napa and Russian rivers.
How do the dead fish nurture our wines? Wild animals eat the salmon carcasses, converting the nutrient-laden fish into fertilizer for the grapevines, according to the study.
I don't lay claim to any original research for this item. It all comes from UC Davis, California's premier wine school, which sent out the information. The study was led by Joseph Merz, a Lodi-based fisheries biologist with East Bay Municipal Utility District and an instructor at Sacramento State University. (The research was funded by the utility district, through its financial support of Merz's doctoral study on restoring salmon spawning.) Merz's research collaborator was his former Ph.D. adviser and the leading authority on California native fishes, Peter Moyle of UC Davis.
Davis' release explains that "…Merz and Moyle examined what happens after Chinook salmon incorporate the rich chemistry of the northern Pacific Ocean (carbon, nitrogen, phosphorus and more) into their body tissues, then carry it upstream in fall and winter to their inland California spawning grounds.
"By tracing the movement of elemental 'fingerprints' called nitrogen isotopes, the scientists found that when the salmon die upstream after spawning, natural scavengers [turkey vultures, coyotes, raccoons and the like] move the marine-origin nutrients into the terrestrial food chain -- either through their wastes or by dropping fish carcasses onshore."
Before long, the nutrients travel through soil and water into wine grapes being grown along the riverbanks, the authors concluded.
"What we found is that the grapes close to the river get up to 25 percent of their nitrogen from salmon," Merz said. "In wine making, nitrogen affects yeast growth and sugar fermentation. No doubt some of the best California wine has salmon in it."