Traditional field research combined with new technology has revealed a secret to the survival of juvenile salmon as they form in their eggs, especially in low-water years when many do not survive, new research from NOAA Fisheries and the University of California, Davis shows.
Sacramento River winter-run Chinook salmon are California’s most endangered salmon, with a single surviving population and an average of a few thousand returning fish in recent decades. Shasta Dam blocks their original habitat in cold mountain rivers draining Mount Shasta, leaving them to spawn in the low-lying Sacramento River heated by the summer sun.
The research, published this week in Science Advances, found that cool river temperatures in the first 15 days after their eggs were fertilized was crucial for their survival. In warm years with less water, cold water barely covered this critical thermal window, sharply limiting survival in what may become an increasing reality for salmon as the climate warms.
Continue reading at noaa.fisheries.gov.
