I drove north from Sacramento to attend the Salmon Festival in Oroville. I drove straight to the Feather River Fish Hatchery to view the Chinook salmon coming up the Feather River to spawn. The hatcheries were created to repopulate the streams, since the construction of dams have prevented them from moving freely up and down the rivers. Being a Midwesterner, learning about salmon’s life cycle and fragility of their ecosystem has been enlightening. For all my Midwest cohorts, I will try to start this explanation from the beginning.
Salmon are an anadromous fish, which means their life cycle spans in both freshwater and salt water bodies. Chinook salmon are born in the river, swim into the Pacific Ocean up by Alaska through Alaska Bay and begin to head back to the river in two to four years to spawn and die. The Feather River Fish Hatchery raise the salmon from artificially fertilized eggs they retrieve, and release them in San Francisco Bay. The salmon return “home” to spawn. It is unsure as to how exactly salmon detect their natal streams, though it is suspected that scents and chemical cues, as well as the sun, play an important role in the homeward migration. Once the salmon reach freshwater, they stop feeding. During the course of their journey, their bodies instinctively prepare for spawning. The taxing journey draws energy from their fat storage, muscles, and organs, except for the reproductive organs. Males develop hooked noses, or kype, in order to fight for dominance.
At the Feather River Fish Hatchery as the salmon return home to spawn, they are blocked by a barrier dam and diverted into a fish ladder. The fish ladder funnels them to the gathering tank. Inside the spawning operation area, the fish are first placed into the tranquilizing tank where carbon dioxide is added to the water. The nontoxic chemical displaces the oxygen in the water, slowing the fish down so the workers can handle them.
The fish are then sorted – those not ready to spawn swim through channels to the holding tanks. Those “ripe” for spawning are artificially spawned. I got to witness this process through the windows in the hatchery spawning building. During the spawning operation, both male and female salmon are killed. (All Pacific coast salmon die naturally after spawning.) The female salmon’s body is slit open along the body line. By hand, the worker scoops out the female salmon’s eggs – 2,500 to 5,000 – into a plastic tray. The milt is squeezed from the males and mixed into the eggs for fertilization.
The edible spawned salmon are donated to local charities and Native Americans.
Steelhead salmon – Because steelheads do not die after spawning, the process is handled differently. The eggs are removed from the female by using low-pressure air injected into the abdominal cavity through a hypodermic needle. Milt taken from the male fertilizes the eggs. Both male and female are then returned to the river.
I have to say, upon leaving the hatchery I felt a bit confused and saddened by the whole recreated artificial ecosystem. I equate it to going to the state fair and watching all the 4-H kids when prizes for their blue ribbon livestock that they have raised up, only to be auctioned off to be bred or slaughtered. Does this artificial ecosystem really benefit our environment? Could we do more to enhance the salmon’s ecosystem? I have scheduled to talk to my coworker, Barry, who is a retired US Fish and Wildlife employee living in Alaska to find out his take on it. If I learn more, I’ll write it
Article: Oroville Spring run Chinook Salmon Population Hits a Historic Low here.
That’s one job I would not like!