 adipose fin clipped).
Salmon are also checked for other identification, including radio transmitters on the right side of their dorsal fin, a spaghetti tag on the posterior end of the dorsal fin or a tagging scar, which can be present in both locations.
All of this information is obtained by taking recordings of the fish as they pass through a chute at the weir where an underwater video camera with a motion detector is mounted.
Fisheries biologist Jeff Breakfield sorts king salmon near holding tanks at the Kasilof hatchery. Eggs from three female fish are mixed with the milt of three male fish in a bucket and then packaged in bags for shipment.
Photo by M. Scott Moon
Breakfield said fish also are manually sampled one day a week by taking scales to determine the age and sex of both hatchery-produced and wild king salmon. These sampled fish are then placed in a holding pond for the second part of the Crooked Creek facility’s work brood stock collection.
Mary Krusen and Sarah Glaves pour the fertilized eggs from three king salmon into a heavy plastic bag for shipment to the Alaska Department of Fish and Game's hatchery at Fort Richardson near Anchorage. The young salmon that hatch from the eggs will be released into the Kasilof River and Sport Lake near Soldotna.
Photo by M. Scott Moon
“We spawn the fish there,” Breakfield said, in regard to how the collection takes place.
To do this, Breakfield dons rubber waders and, using a net, crowds the fish into a small section of the pond where he can ensure that only wild kings are caught for collection and that these fish which typically range from 15 to 40 pounds are ready to spawn.
All other salmon hatchery-produced and wild fish not quite at their reproductive peak are passed upstream to spawn naturally. Breakfield said it’s really quite simple to discern which fish are ready for spawning.
“The hens will look ripe. They’ll be colored up with bellies that are sagging and soft to the touch. You’ll also see single eggs coming out of them,” he said.
As to the male fish, Breakfield said he doesn’t even have to check them.
“All the bucks are ready to go,” he said.
Dozens of freshly collected king salmon eggs fill a heavy plastic bag at the Alaska Department of Fish and Game's hatchery on Crooked Creek in Kasilof during an "egg take" by department employees. More than 100,000 eggs will be collected there this summer and then trucked to a facility at Fort Richardson, where they will be raised for release into the Kasilof River and Sport Lake.
Fish determined ready to spawn are then humanely euthanized, and the creamy, white milt of males and the translucent, cherry-colored eggs of females are harvested by milking them into a five-gallon bucket. The spawning ratio is one to one, with three females and three males milked per bucket.
“We squirt the milt of a buck into the bottom of the bucket, then we put in eggs from three hens, then the milt of two more bucks on top,” Breakfield said.
The average number of eggs produced by a female is roughly 5,900, according to Breakfield. “This year we have some really good hens, though, so the average was around 6,600 eggs per hen, and we did egg-takes on 27 hens, so we’ll probably end up with around 178,200 eggs total.”
Once milt and eggs are in the bucket, they are carefully mixed to further ensure fertilization. Then water is swirled into the bucket to harden the eggs. This water comes from the Fort Richardson State Fish Hatchery near Anchorage, where the fertilized eggs are then shipped.
“Using water from Fort Richardson ensures that disease can’t be transferred to the hatchery if there is any present in the water at Crooked Creek,” Breakfield said.
At Fort Richardson, the eggs are put into incubators to hatch into young salmon called alevins that have big, bloated yolk sacks dangling from their abdomens.
Once these yolk sack reserves are absorbed, the young fish become fry and are transferred to outdoor holding pens where they are fed and continue to grow to roughly 5 grams in weight and between four and five inches in length, at which point th