“To survive, there are two things a salmon needs”

from an unpublished book: "What is it going to be then, eh?
story and drawings by Marguerita

“To eat. And not to be eaten.”

Where did they go?
The Chinook salmon that swim upstream to spawn in the fall, the most robust run in the Sacramento River, have disappeared.The fishermen think the fish were left susceptible to disease, or to predators, or to being sucked into diversion pumps and left to die in irrigation canals.The life cycle of these fall run Chinook salmon takes them from their birth and early weeks in cold river waters through a downstream migration that deposits them in the San Francisco Bay when they are a few inches long, and then as their bodies adapt to saltwater through a migration out into the ocean, where they live until they return to spawn, usually three years later. “the fish that went to sea in 2005 died a few weeks after getting to the ocean because there was nothing to eat."
So what happened?
http://www.nytimes.com/2008/03/17/science/earth/17salmon.html?hp