Even the experts still aren’t sure. But The San Francisco Chronicle, in the person of Jane Kay, follows up, and brings a little more specificity to the question. Still no mention of La Nina/the PDO, but buried deep in the story is the news we half-expect, half-fear:
In 2005 and 2006, the years
that the 2007 [chinook] fall run needed food near the shore in the Gulf of the
Farallones, the upwelling of nutrients apparently came too late to
produce the small fish that feed the salmon.
Most of the scientists studying the ocean link the unexpected bouts
of rising temperatures to global warming. As the atmosphere and oceans
have warmed, researchers have had to discard the theory of decades of
warmer, then cooler, ocean temperatures. Now they expect an
unpredictability, which is projected in climate models.
"What’s happening is that the rockfish, the squid, the krill, the
anchovies and the community of critters that salmon feed on changed
dramatically in 2004 to the prey that is not as favorable to salmon,"
NOAA’s Ralston said.
Next question: What is this unpredictability that Kay speaks of? How is it measured? And can we portray it graphically?
Kit Stolz 