Fish Species
The Warm Springs National Fish Hatchery (NFH) is somewhat unique
in that the Warm Springs River, located on the Warm Springs Indian
Reservation, is "home" to both wild and hatchery spring
Chinook salmon.
The
Confederated Tribes of the Warm Springs Reservation of Oregon and
the U.S. Fish and Wildlife Service agree that the wild fish and
hatchery fish should be kept separate as much as possible. The fish
apparently spend their smolt and adult time together during their
journeys to and from the Warm Springs River - in the Deschutes and
Columbia Rivers - then they go their separate ways.
Adult salmon return to Warm Springs River from April to August. There
is a man made barrier at the hatchery site that directs returning
adults to a fish passage system. This system allows wild spawned
adults and other fish species to by pass the hatchery. Fish are guided
through a fish ladder leading to a sophisticated magnetic sensing
device that detects very small metal tags placed in all hatchery
reared fish 4 years earlier when they were 3 inches long. When a
tag is detected, a passageway tube lifts dropping the fish into a
catch pond. When no tag is detected, the passageway tube stays in
place and the fish is allowed into the upriver channel where it can
proceed above the barrier. Several times a week the captured fish
are inspected to make sure that no wild fish are retained. Occasionally
this may happen if a fish has some metal in their mouth or body such
as a portion of a hook. Adults that originated at the hatchery are
directed to one of 2 holding ponds. An underwater camera runs constantly
on the "upriver" side. Those video tapes are read at least
twice a week to make sure only wild fish are proceeding upriver.
Once again, that check is made visually by seeing whether or not
there is an adipose fin on the fish.
The returning Spring Chinook salmon do not feed and are maintained
in the holding ponds until they are manually spawned in August and
September initiating the beginning of another life cycle. The eggs
are incubated in trays for about 90 days till they hatch, depending
on water temperature the newly hatched fry can stay in the trays
for 60 days when they are transferred to larger tanks. After they
outgrow the tanks and the water warms outside in the spring, they
are moved to outside ponds until release into the Warm Springs River
the following year.
Wild adults that move upstream of the hatchery
spend the warm summer months loafing in deep cool pools and begin
normal spawning behavior in August and September. The eggs are incubated
in gravel nests, the newly hatched fry remain hidden in the gravel
interstices until they are ready to swim up into the river current.
When they begin the smolting process, they leave on their own down
the Warm Springs River.
How do we tell the wild fish from the hatchery fish? When fish
are moved to the outside ponds they are about three inches in length.
At this time they are "marked." At the Warm Springs NFH,
the adipose fin is clipped off and a coded wire tag is implanted
in the fish’s snout. The tag has a distinctive numeric sequence
embedded on it. The code allows biologists to determine where the
fish came from and any other data, such as which pond it was in at
the hatchery.
The Confederated Tribes of Warm Springs and the U. S. Fish and Wildlife
Service have agreed that up to 10% of the fish that go upriver can
be of hatchery origin, that is, not have an adipose fin. At such
time that more than 10% hatchery salmon go upriver, the passageway
will be closed and the incoming adult salmon will be hand sorted
by adipose fin. At hand sorting, a manual detector can be used to
check tags, if necessary
