The centuries-long erosion of California's wild salmon
For nearly 200 years, Pacific salmon have suffered a one-sided war of attrition.
Unsurprisingly, they’re losing.
Faced with record population lows, officials banned salmon fishing in California and much of Oregon last month. In 1995, over one million chinook salmon returned from the Pacific ocean to their spawning rivers. This year, that number is projected to be less than 170,000.
The future of California’s native salmon looks bleak. But humans have fished salmon sustainably along the West coast for thousands of years. What changed?
We’ve been chipping away at Pacific salmon for centuries. 19th century western expansion transformed the landscape of California, ushering in dramatic population growth and industrialization. An extensive network of dams and reservoirs blocked cooler water found at high elevations from making its way down river. Not only were many salmon unable to make it back to their home tributaries beyond the dams, but also warm water throws off their metabolic, behavioral, and developmental cues, finely-honed by millennia of evolution.
Before these anthropogenic changes, nearly 1,400 Pacific salmon subpopulations existed along the West Coast of North America. Today, nearly one third of them are extinct.
California has always provided a dynamic, unpredictable habitat for its wildlife. The varied terrain and boom-bust precipitation cycles engendered adaptability and resilience among its salmon. The five Pacific salmon species breed and migrate at different times throughout the year, spreading the risk of unfavorable conditions across generations.
But climate change is tipping the scales. Conditions are becoming more extreme – summers are getting drier, winters are getting wetter, and oceans are getting warmer. Despite their adaptability, wild salmon are losing ground. This year’s ban was preceded by several years of severe drought in California, which had already decimated native stocks.
Solving this problem is more complicated than simply replenishing native stocks with farm-raised or hatchery fish. Hatchery-raised salmon weaken the genetic diversity and survival instincts of wild stocks, increasing Pacific salmon’s vulnerability to drought and predation.
Wiping out keystone species as culturally and economically significant as Pacific salmon is not an option. Wildtype offers a choice beyond wild or farm-raised salmon – one that can take the pressure off our oceans and rivers and give them a chance to recover.