In this podcast, Melin explains that unusually warm water along the Pacific coast has sent sardines, anchovies, and other prey species north or deeper in search of cooler water. As a result, sea lion mothers are having trouble finding enough food to nurse their pups.
Many of the pups eventually set off on their own desperate search for food. But the pups, weak and lacking the experience they need to forage on their own, wash up on the mainland instead.