Return of salmon to California’s once-dry San Joaquin River is spawning toward recovery, one egg at a time
It’s salmon squeezing time at California’s newest, most technologically-advanced fish hatchery. Standing in a large tank filled with 54 degree water, a fish technician passes an ultrasound wand across the abdomen of an adult female Chinook salmon to ensure its eggs are fully developed. If so, techs then squeeze out some eggs from the salmon’s belly while feeling for the looseness of the remaining eggs. Each ripe female is then transported into a separate holding tank for spawning the following day. Male broodstock get similar handling, except the squeezing is employed to express milk. The males also get scanned (via a transponder tag embedded in their abdomen) to determine which are the least genetically related to the females. Why? Because the last thing biologists want, especially when resurrecting a salmon run that was killed off for more than six decades, is inbred fish.
Other Sacramento-San Joaquin Delta news:
