But even as long ago as the 1890s, fishermen, public officials, and Oregon's coastal communities voiced alarm at a precipitous decline in the size of salmon runs. In the early part of the 1900s, canneries disappeared from the shores of many of Oregon's estuaries. More recently, since the 1960s, commercial salmon fleets have come and gone as well. Today's limited recreational and commercial fisheries rely on hatchery-produced fish. If salmon seasons are opened at all, they are carefully monitored to minimize the number of wild fish that are caught or landed.
Hatcheries produce millions of fish that are released to migrate to the ocean and back.
However, hatchery fish are not as genetically robust as native populations. Hatchery fish can also have decreased resistance to diseases. In some cases hatchery fish have spawned with wild salmon, thus reducing the genetic resilience of the wild salmon population. Dams present a significant barrier to migrating fish. They create slack-water pools where fish expect tumbling water.