The Lewiston Tribune –
Adult returns of Snake River salmon and steelhead are the gold standard when measuring efforts to recover the imperiled fish. And by that standard, we don’t have much gold.
It’s simple — in order for the runs to persist, enough juveniles that migrate to the ocean must survive and ultimately return as adults to produce the same number of smolts to repeat the cycle. In the Snake River that means 2 percent of smolts must survive and return to spawn just for the runs to hold steady. To grow the runs, returns have to average 4 to 6 percent.
Thus the region has long held a goal of reaching smolt-to-adult return rates, or SARs, of 2 to 6 percent.
“It’s established as the goal because the actual currency is adults coming back,” said Michelle DeHart of the Fish Passage Center at Portland. “So smolt-to-adult captures the whole life cycle survival. You have a number of smolts going out and what number of adults coming back from that number of smolts is capturing everything that happened to those fish.”
A return of 2 percent is basically breakeven. It’s like making just enough money to cover your bills.