Extinct Pacific Salmon Populations in the USA
Population Extinctions
Scientists estimate nearly 1400 genetically-isolated Pacific salmon populations once spawned from California to southern British Columbia. Due to dam building and other alterations of lakes and rivers, 406 or 29% of the salmon populations have become extinct in the last 240 years.
| Common Name | Scientific Name | Extinct | Surviving |
|---|---|---|---|
| Steelhead | Oncorhynchus mykiss | 131 | 436 |
| Chinook | Oncorhynchus tshawytscha | 159 | 237 |
| Sockeye | Oncorhynchus nerka | 34 | 38 |
| Coho | Oncorhynchus kisutch | 50 | 135 |
| Chum | Oncorhynchus keta | 23 | 89 |
| Pink | Oncorhynchus gorbuscha | 9 | 42 |
Regional Losses
In many cases, salmon have retreated from an entire region. Out of 13 ecological regions where wild salmon spawn from California to Idaho in the western United States, nine have lost one or more species of salmon since 1770.
| Salmon Species | Gone From |
|---|---|
| Steelhead | Upper Snake River Columbia River headwaters |
| Chinook | Southern California Northern coastal California Upper Snake River Columbia River headwaters |
| Sockeye | Upper Snake River Mid Columbia River Columbia River headwaters |
| Coho | Southern California Lower Snake River California Central Valley Mid Columbia River Upper Columbia River |
| Chum | Northern coastal California California Central Valley Mid Columbia River |
| Pink | Northern coastal California California Central Valley Klamath Mountains Province |
Reference
Richard G. Gustafson, Robin S. Waples, James M. Myers, Laurie A. Weitkamp, Gregory J. Bryant, Orlay W. Johnson and Jeffrey J. Hard. 2007. Pacific Salmon Extinctions: Quantifying Lost and Remaining Diversity. Conservation Biology. 21(4): 1009-1020.
