Alarmingly low numbers of baby salmon are surviving their journey down the Sacramento River to the sea, confirming conservationists’ fears that low flows and high river temperatures during the drought would wipe out most of the endangered winter-run salmon born last year. Only 2.6% of the eggs that winter-run chinook salmon laid in the Sacramento River resulted in fry, or inch-long baby salmon, according to a report from the state Department of Fish and Wildlife made public on Monday. Used to monitor and project the health of the population, this “egg-to-fry” survival rate is the first official estimate of baby salmon born last year and the lowest in the past two decades.

Low numbers of baby salmon portend disaster for endangered California fish