Collapsing Chinook Salmon Runs? (Hardwear Sessions)

By Cynthia Houng

This fall, the chinook salmon run dried up.

Residents of the San Francisco Bay Area have come to associate fall with the annual chinook salmon run. The fish make their way up the Sacramento and San Joaquin Rivers, back to their spawning grounds, providing both humans and animals with rich, satisfying protein.

At their peak, the chinook numbered in the hundreds of thousands. Up to 800,000 fish have been recorded by fishery officials. This year, some 90,000 salmon made the trip upstream. Most years, 250,000 salmon find their way back to their spawning grounds.

Most readers know the chinook as the "king" salmon. The salmon fishing season typically opens in April or May. During that time, the fish graces many Bay Area tables. Many noted Bay Area restaurants, including Berkeley's Chez Panisse, favor the king for its silky flesh and delicate flavor. This year, however, the Pacific Fishery Management Council, which regulates West Coast fisheries, will set limits on the 2008 salmon season, driving up prices. Many fishermen fear for their livelihoods, for the salmon runs represent their bread-and-butter.

According to the Pacific Fishery Management Council, this precipitous drop in chinook numbers is particularly distressing for two reasons: (1) the adult spawning escapement failed to meet the escapement goal for the Sacramento/San Joaquin river basin; (2) the count of "jacks" (or immature fish) returning to California's Central Valley was also a record low.

Together, these two sets of numbers paint an ugly picture. The "escapement goal" is particularly important, because this number represents the "optimal number of adult fish returning to spawn in order to maximize the reproduction of the stock." If adequate numbers of reproduction-age chinook fail to return to their spawning grounds, the chinook fishery's long-term health will be in jeopardy. Fishery officials use the number of "jacks," or immature salmon, to forecast future chinook numbers. This year, only 2,000 jacks returned to the central valley. In normal years, about 40,000 jacks return to the Central Valley. The previous record low was 10,000.

Some scientists are already describing the chinook fishery as a "collapsing" fishery. But few can say why the chinook fishery is collapsing. Some suggest that long-term climate change may be the root cause, others point to the changing Central Valley landscape. Farmers and fishermen have long battled over the Sacramento and San Joaquin watersheds, and there is evidence to support the theory that the Central Valley's extensive network of dikes and dams have done great damage to the Valley's fisheries.

But whatever the root cause--or more likely, causes--the spring of 2008 will go down in history as one of the worst years ever, for both the Central Valley chinook and Bay Area fishermen.

Read more about the Central Valley chinook: