Good article with the caveat that it places salmon well-being above human well-being and doesn’t understand the social evolution of many species that have to interact with human beings which, just as urban humans have had to do in relation to their natural and wild past, adapt to the urbanization of our planet.
In this case, human beings need water, and dams store water. Dams also restrict natural salmon spawning habitat, which humans have addressed through hatcheries and the release of cold water from dams to lower reaches of rivers where salmon didn’t normally spawn, but now can due to the cold water release.
Spring 2007 Issue
The State of the Salmon
by Eric Winford
A rough estimate on the number of chinook salmon that returned to spawn in Central California rivers in 2006 is 350,000. Although that figure sounds impressive at first glance—and is, indeed, a substantial improvement over the low runs of the early ‘90s—it represents only a fraction of California’s historic salmon population.
The majority of those returning chinook, about 290,000 of them, ran upstream in the fall. The rest came in California’s other runs: late fall, winter, and spring. These runs are designated "evolutionary significant units"—each reflecting a unique adaptation to local conditions, each representing a unique genetic code, and each worth preserving.
"California is unique in that we have four distinct runs of salmon," explains Tina Swanson, a senior scientist at the Bay Institute of San Francisco.
California’s rivers once swam with millions of salmon. In the 19th century, annual accounts commonly reported one to three million chinook in the rivers draining the Sierra Nevada. The spring-run chinook historically returned to spawn in the largest numbers, prior to losing 90 percent of their habitat to dams, diversions, and destruction.
The returning salmon climbed as high as 6,000 feet up rivers swollen with melting snow. They existed in 17 geographically distinct populations in the Sacramento and San Joaquin watersheds, but now they are reduced to spawning below dams in the few rivers that can support them. They have been entirely eliminated from the San Joaquin watershed, and federal and state agencies have listed spring-run chinook as a threatened species.
The winter run is listed as an endangered species on both state and federal lists. Its population fell to 211 in 1991, and although numbers have grown to a recent estimated peak of 17,000, the run is still considered endangered because the majority of the wild population spawns in only one place: below Shasta Dam. Restoration of Battle Creek allows some portion of the wild population to use that habitat.
