A salmon in the wild. Credit: Cramer Fish Sciences

Salmon are becoming river "ghosts" as brutal droughts and violent floods cause unprecedented losses on their treacherous journey to the Pacific Ocean, scientists say. A study led by the University of Essex; NOAA Fisheries; University of California, Davis; and Cramer Fish Sciences has found that young Californian Chinook salmon face a deadly double threat from extreme weather and the destruction of historical wetland habitats they rely on.

The study emphasized how deadly droughts are for young fish and how they thrive in wetter conditions. However, the results also indicated that in modern, simplified rivers, extreme flows during winter storms can be devastating too.…