hatchery

For decades, government-run hatcheries in the Central Valley have reared and released millions of salmon each year to help boost their numbers.

In October, the state Department of Fish and Wildlife constructed a series of nests along the 12-mile stretch of gravel riverbed and then filled them with fertilized Chinook salmon eggs from a nearby hatchery.

They’ll need to be transferred into hatchery trucks outfitted with large tanks.

Now the delta smelt is functionally extinct in the wild, the species preserved only through a state and federal hatchery program, the success of which is uncertain.

As detailed by National Geographic, it is a common practice in salmon hatcheries to harvest salmon sperm, which requires a scientist to squeeze a salmon in the right spot — also known as abdominal massaging.