A Chinook is a Chinook - Not

Those of us that live up-River of Riggins are sure hoping that IDFG will limit the lower Salmon River Chinook harvest, so as to allow a decent adult return to the upper River, especially the Pahsimeroi, and Sawtooth hatcheries. After all, is this not the "seed" that feeds the entire River....????  Darren


The Chinook salmon running back to Idaho don't leave the ocean to begin their return journey to spawning streams or hatcheries at the same time.  The earliest Chinook to cross Bonneville Dam are headed to the Clearwater River, Snake River, and Little Salmon River systems.  We know the timing because a small percentage of fish have PIT tags that are read in the fish ladder as they swim over the dam.  This allows us to estimate the population of returning salmon several weeks before the fish reach Idaho.  This is why we set the Chinook salmon season and bag limits for lower river fisheries in March.  A few weeks later, we see PIT tagged fish headed for the South Fork Salmon River pass Bonneville Dam.  Once we have a good idea of the population size, based on the PIT tag information, we set the season and bag limit at the May Commission meeting for the South Fork Salmon River.  The last fish to pass Bonneville Dam contain PIT tags that tell us that they are headed for the upper Salmon River and the Sawtooth and Pahsimeroi Fish hatcheries.  That's why the Upper Salmon River season and bag limit is set last.  Typically, by the time Upper Salmon Basin salmon pass Lower Granite Dam and enter Idaho, the lower Salmon River and Clearwater River seasons are closed.

The three different salmon groups all spawn around the same time (early August thru early September).  Because Chinook salmon can no longer utilize food once they leave the ocean, biologists believe this segregated timing of the fish leaving the ocean is a stratagy to optimize survival to spawning time.  So, the fish that swim the farthest are the last to leave the ocean (they build their strenth in the ocean for as long as they can before starting their "death-swim" to the Stanley Basin).  Chinook in the lower Salmon and Clearwater have an easier journey and expend less energy on the trip.  Consequently, they leave the ocean earlier and can live long in fresh water living on their fat reserves.

Most Chinook salmon return to the stream or hatchery where they "smolted" or began the journey from Idaho to the ocean. So, not all Chinook salmon that enter the Salmon River are headed to the Stanley Basin.  -  dparrish