Officials are expected to shut down all commercial and recreational salmon fishing in California and much of Oregon for 2023 due to a significant decline in fish stocks, linked to engineered waterways and the effects of climate change. Now, less understood oceanic threats could also be tied to global warming, researchers say.
Salmon counts were worse than anticipated, with fewer than 170,000 fall-run Chinook expected to return to Central Valley rivers, down from over a million in 1995. Nate Mantua, a climate scientist at NOAA Fisheries, warned that “California salmon are in dire straits,” and the situation may foreshadow what is to come in cooler waters farther north.
California’s salmon have faced challenges from fur traders, hydraulic mining during the Gold Rush, and dam construction. The state lost about 90% of its wetlands, and climate change is exacerbating these issues. The commercial salmon industry plans to request federal disaster relief and argue that water allocation for agriculture is part of the problem.
Several salmon varieties are already listed as threatened or endangered in California, and hatchery efforts for the fall-run Chinook might be backfiring by weakening the fish’s genetic resilience. Ocean forces have also contributed to total shutdowns of salmon fishing in California in 2008 and 2009. An El Niño pattern is predicted to appear, which could worsen the situation.
On a positive note, the removal of four old hydroelectric dams on the Klamath River will give salmon access to over 400 miles of historical habitat. Additionally, salmon advocates are working with farmers to create win-win solutions, such as using rice fields as temporary floodplains in the winter, allowing young salmon to grow and recharge groundwater while fertilizing rice fields.