You may not think that a hatchery is a place that moves with
the seasons. Especially a place like Dworshak, the asphalt, concrete, and steel
don’t conger thoughts of natural processes. By design a hatchery is built to
keep fish in and keep their natural predators out. But when you look beyond the man-made ponds
and the bird-netted enclosures, when you look at the fish that are reared here,
you can see there is a rhythm that is followed. Winter, spring, summer, and fall
all hold specific milestones for each brood of fish reared here.
Winter
 |
| Chinook Alevin |
Like the stillness after a snowfall, winter is a time of calm
and preparation at the hatchery. Chinook eggs hatch and alevin quietly develop
in the darkness of the incubators. Juvenile Chinook and Steelhead feedings decrease
as the water temperature drops and days shorten. Hatchery staff use the winter months to
prepare the nursery for the busy spring by completing annual maintenance and
preparing the 128 tanks for steelhead fry arriving in March. Winter is also the
time that staff PIT tag our juvenile steelhead, Coho, and Chinook. Of course
steelhead spawning begins in winter but is also one of the signals that spring
is on its way.
Spring
 |
| Out-planting steelhead smolts |
As the days lengthen and the osprey arrive the pulse of the
hatchery begins to pick up. Our Juvenile fish are smolting, ready to make the
journey to the great Pacific. Their release is timed as the spring rains, and
snow run off raise the water in the Clearwater River. Almost simultaneously the
Chinook fry are ready to be ponded. It’s a mad dash to clean, upgrade, and
prepare the raceways for the hungry fry. The steelhead eggs that were spawned
in the winter are eyed up and ready to be moved into the nursery. Earlier takes
have hatched and are ready to start feeding. Like busy bees tending a hive,
hatchery staff feed the baby fish 8 times a day, 7 days a week. There is a lot
of spring cleaning going on too. Because of all the feed, nursery tanks require
daily cleaning. Chinook raceways are cleaned at least three times a week. All
the empty Burrows Ponds need to be cleaned and disinfected before the next
brood of steelhead can be ponded outside. As spring transitions to summer the Kings
of the Clearwater, the Spring Chinook, make their first appearance.
Summer
 |
| Splitting Steelhead |
 |
| Opening the fish ladder |
Now the sun is high in the sky. The days are long and hot; we
are all wishing that the Dworshak asphalt was lawn and the Burrow’s ponds were
swimming pools. The fish ladder is opened for the first time since March. We
begin trapping Adult Chinook and preparing the incubators for their progeny. The
steelhead and Chinook that were ponded in the spring are growing like
gangbusters and are beginning to outgrow their homes. Summer is when fish in
the nursery are moved outside. The tagging crew is here marking fingerlings as
hatchery fish by the removal of their adipose fin. The fish grow even more.
They outgrow their homes again! Now the crew splits fish from one Burrows pond
or raceway into three. The transferring, marking, growing and splitting continue
into fall.
Fall
 |
| Chinook Spawning |
The
pace is beginning to slow, a little. There are Chinook and Coho to be spawned
though. We spawn Chinook in September and Coho in October. We keep the eggs on
chilled water to make sure they develop in tune with their natural cycle. The
eggs will slowly and quietly develop through the fall hatching as fall rolls
into winter. Things truly begin to slow down. The fish that are outside aren’t eating
quite as much. The nursery is empty. The daily feeding and cleaning schedule
lightens. Demand feeders for steelhead come out. The osprey leave, the eagles
arrive. Was that a snowflake?
Photos and text by: Angela Feldmann
