RIVERDALE - The future of North Dakota's salmon fishery is once again swirling in small rearing tanks inside the Salmon Building at the Garrison Dam National Fish Hatchery. It is there that thousands of newly hatched chinook salmon have emerged from battery jars and have begun to absorb their life-giving yolk sacs.
Once the yolk sacs are absorbed, the tiny fry begin the transition to small artificial feed. It is also a time when slow-developing or weak fish will die. Even in the controlled environment of a fish hatchery, it is survival of the fittest.
"Newly hatched fry are especially vulnerable. We will have some die off," said Sean Henderson, Garrison Dam National Fish Hatchery. "We're shooting for stocking 200,000 in the fall of 2013."
North Dakota's landlocked salmon do not reproduce on their own. Salmon eggs are brought to the hatchery each fall by biologists from the North Dakota Game and Fish Department. Biologists artificially harvest the eggs from salmon captured in Lake Sakakawea and the Missouri River. As part of the U.S. Fish and Wildlife Service cooperative agreement with NDG&F, the federal hatchery raises the salmon until they reach fingerling size. Then Game and Fish returns to stock the fingerlings into North Dakota waters.
"We had about 300,000 eggs to start with," said Henderson. "We get a lot of bad eggs mixed in with the good, but the earliest developed fish, those spawned Oct. 3, look pretty good. We're heating the water temperature up to about 54 or 55 degrees, which is just right for these guys to help get them over this stage of development."
Henderson recently joined the Garrison Hatchery staff, arriving from his previous position at the federal hatchery in Ennis, Mont. At the Ennis facility, Henderson handled the brood stock program that produces 20-million rainbow trout annually with shipments to as many as 30 states. Ironically, when Henderson arrived at the Garrison Hatchery, he was charged with overseeing an indoor raceway containing rainbow trout that were produced from eggs shipped from Ennis.
Sean Henderson, Garrison Dam National Fish Hatchery, oversees production of the hatchery’s cold water species — trout and salmon. Here Henderson checks on the status of recently hatched chinook salmon.
These chinook salmon fry were still absorbing their yolk sacs when this photograph was taken Nov. 26. Once the yolk sacs are completely absorbed and the fry are established on feed, they will be transferred to a much larger indoor raceway.
"I was interested in developing my career," explained Henderson when asked about his decision to move to North Dakota. "Here I get to work with different strains of rainbows, cutthroats, browns, chinook salmon, and they've got a number of other species too. It's another opportunity."