This is a wonderful story, from the Sacramento Bee, about the capability of human technology to restore spawning sites for salmon, which are needed due to the other wonderful human technology story—the building of dams on the American that save Sacramento from flooding and produce hydroelectric power—and, along with hatchery technology, can do a lot to keep the salmon run in the American rich and productive.
“New fish spawning areas in the American River are bristling with fresh nests of steelhead eggs – so many that officials urge anglers and others not to wade in the area.
“Salmon and steelhead breed by laying eggs in riverbed gravel. They use their powerful tails to sweep out circular nests in the gravel to hold their eggs.
“Appropriate gravel is in short supply, however, due to a century of dam building, mining and other activities.
“To address this problem, hundreds of truckloads of gravel were spread in two riverbed areas just downstream from Nimbus Dam over past the two years in a joint project by the Sacramento Water Forum and U.S. Bureau of Reclamation.
“The project has succeeded in coaxing more fish to lay eggs in the American River. Salmon and steelhead have created at least 347 gravel nests – also called "redds" – in the restored areas, according to surveys by Cramer Fish Sciences, a consultant hired to monitor the project.
“Joe Merz, a senior scientist at Cramer, said the salmon and steelhead redds counted this year could produce nearly 800,000 young fish.”