Idaho’s Kokanee Hatcheries

Idaho’s Kokanee Hatcheries


Fishing for kokanee on a warm spring day
is months away, and Cabinet Gorge Hatchery is still buried under snow. But Fish and Game staff are counting down to summer. Cabinet Gorge is one of two designated hatcheries for Idaho Fish and Game’s
kokanee program. Right now, kokanee fry are being fed a highly regulated diet to
coax them to grow to 3 inches by May. These kokanee fry are at the halfway
point of a year-long process. It all starts in August when coolers filled
with early spawning kokanee eggs arrive from Deadwood Reservoir. After the eggs come in from Deadwood, we
put them in upwelling incubators and when they get to the eyed egg stage, we
take the eggs out of the jars and run them through an egg-picking machine. The machine will sort the live eggs from the dead eggs. The egg sensor will sense a
bad egg when the light doesn’t go through it, and it releases a little bit
of air and it will pop that egg out and into our dead egg side of the bucket. We usually get about 90 percent good eggs, 10 percent bad eggs. At that point, we take the good eggs
and put them back into the incubators. After about another three weeks of
development, the eggs will start hatching. As they hatch and develop and absorb the
yolk sack, they will swim out of the incubators into these vats. At that point,
they become what we call swim-up fry – when they swim up, that’s when
we start feeding them. Not all kokanee eggs that
start at Cabinet Gorge Hatchery are raised here. Upwards of three million eyed-eggs are
trucked 400 miles south to Idaho’s other kokanee hatchery in Mackay. Those will
come down probably in three shipments – roughly a million at a time. So we drive
up one day, load coolers early in the morning, come back, and then you put eggs away here. They are incubated for a couple weeks,
then they’ll hatch. After about three weeks, they will absorb that yolk sack, and
be what we call the button-up stage and swim-up fry.
They will then be put into our hatch house rearing vats and we start feeding
them lightly and we’ll start moving them outside to production raceways like
these about middle of February. Shifting kokanee production to Mackay
Hatchery is all about water temperature. Water at the Mackay Hatchery is four degrees warmer than Cabinet Gorge. All fish are cold- blooded animals, so the colder the water
the less feed you can pour to them the slower the growth rates are going to be.
So I have more latitude and can push fish a little faster down here if needed
then they can at Cabinet Gorge Hatchery. Food is manipulated so that certain
groups of fish grow to three inches by a target date for planting in specific
waters around the state. Half of our fish leave in May, about half leave in June, so
we have to know as they go out which fish are destined for certain lakes and
reservoirs so that we can program their growth rates to make a 3-inch fish
in May for one group, a 3-inch fish in June for another group. Kokanee grow
quickly. Depending on the water temperature and food, these fingerlings
will grow to 10 to 13-inch fish in a year. After another 12 months, the fish will be
14 to 17 inches, and hopefully, dangling on the end of a fishing line.

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