Along the sun-warmed reaches of the Sacramento River, a critically endangered salmon population numbering only in the low thousands clings to survival through a window of time no wider than fifteen days. Scientists have now confirmed what water managers long suspected but could not prove: the thermal conditions a salmon egg encounters in its first two weeks of life determine, with near-mathematical certainty, whether that life will continue. Each degree of warming closes that window further, and with Shasta Dam blocking the cold mountain rivers where these fish once spawned freely, the arithme
Critical 15-day window in egg development determines survival for California's rarest salmon
Sacramento River winter-run Chinook salmon face near-extinction with only one surviving population averaging a few thousand fish, threatening tribal communities and ecosystem health.