6 DECEMBER 15, 2007
Smoke Signals 7
DECEMBER 15, 2007
hi fiDrndl
n
First big catches a testament to Grand
Ronde's Natural Resource efforts
Smoke Signals
wm7
By Ron Karten
Smoke Sinnals staff writer
The storms of early October
swelled Agency Creek and
coho salmon began arriving
at the Tribal fish weir. (The steel
head are expected in late December
or early January.)
These old coho souls were headed
a little further up the creek, where
their ancestors went, to lay their eggs
and settle back for the big sleep.
First, however, Tribal Natural
Resources staff members had a
job to do. They noted the size, age
and sex of each salmon, and netted
them as they swam around in the
little caged space of the weir.
Staffers punched a hole in the fish
gills so if they happened to cross
back downstream, they could come
through the weir again without all
the bureaucratic rigmarole.
It's part of the process of develop
ing a wildlife management plan, said
Tribal Natural Resources Fish and
Wildlife coordinator Kelly Dirksen.
The plan starts the process of
building successful fish habitat
further up the creek "to establish
steelhead in catchable numbers.
To do that, you have to have ac
curate numbers about the num
ber of fish moving upstream,"
Dirksen said.
More than a month after the
first October
storms, the coho
were thicker
than ever in the
weir. On Nov.
13, Natural Re
sources staffers
caught, weighed
and measured
103 fish. That
is nearly four
times more than
the previous
one-day total
of 28, seen two
years ago on the
same creek.
At Willamette Falls to date, 1,166
coho have passed through and 252
have been caught. That appears to
say that more than 20 percent of
the coho in the Willamette Basin
are coming up here, Dirksen and
Tribal engineer Eric Scott, who
designed the weir, said.
"Either their counts are off or we
"We're less than 1 per
cent of the Willamette Ba
sin and we're getting more
than 20 percent of the fish.
That says something pretty
phenomenal about our
habitat and our efforts."
Natural Resources Fish and
Wildlife coordinator
Kelly Dirksen
have some extraordinary habitat,"
Scott said.
The weir itself is the first of its
kind, according to Scott and hy
draulics designer Paul Schwinn,
West Coast Fluid
Power manager
of Cleveland,
Ohio-based Ap
plied Industrial
Technologies.
"One of the
things that
makes it so
unique," Scott
said, "is it can be
put in a stream
that receives a
lot of debris. It's
a self-clearing
system.
However, it's not full-proof. The
mechanism designed to tip the gate
down when debris clogs it stalled
that day.
"We expected to have some bugs
to work out with this thing," Dirk
sen said. "As the only thing like it in
the nation, I think it's reasonable to
have some problems, but so far, it's
been amazingly successful."
"(Operating this weir is) not an
exact science," Schwinn said. "Be
lieve me."
The problem has since been
worked out, but even before that
there was quite a bit of excitement
about how well the weir worked.
"We didn't expect to see anything
like we're seeing," Dirksen said.
"We're less than 1 percent of the
Willamette Basin and we're get
ting more than 20 percent of the
fish. That says something pretty
phenomenal about our habitat and
our efforts."
Computer-driven, the weir's me
chanical functions run on solar
charged 12-volt deep cell batteries.
It's also designed to change the size
of the traps to catch smolt as well as
different sizes and species offish, and
to isolate fish from one another.
Previously built Tribal weirs,
which were far less substantial,
were wiped out by the end of each
season, Scott said. This one is more
than still standing.
It appears to be a giant step for
ward in the Tribe's effort to deliver
the best fish habitat in Oregon, he
said.
i , . X s. v
Q' if
'V,
l.-w..,-. .,;.l -ij-
v t
1 f
J t it
r-j
1 rrr?'.'' --I r
Photos by Ron Karten
Riley Bernard, left, a seasonal biology tech for the Tribe's Natural Resources Division, and Jason Bernards, a new forester for the department, measure and tag
a coho salmon heading up Agency Creek to spawn in the Tribe's new, computer-driven fish weir.
Fish weir explained
In simplest terms, a fish weir is
a tool to capture adult salmon
and steelhead. But the Agency
Creek fish weir is anything but
simple.
Agency Creek has been known to
increase in depth from less than a
foot to more than 8 feet within 48
hours. Logs greater than 4 feet in
diameter and debris rafts larger
than a car have routinely been
seen floating down Agency Creek
in high-water events.
So how do you develop a trap that
can safely catch fish yet withstand
the debris and powerful stream
flows? That is no easy feat. The
design, development and permits
for this project took more than two
years to complete.
The fish weir spans 37 feet across
Agency Creek. The 8-foot-tall weir
gate is made of six welded alu
minum panels with vertical bars
spaced to allow a one-foot gap be
tween the bars.
The panels are welded to a sleeve
and carrier pipe, allowing the panels
to pivot from the bottom across a sill
(concreted footing). The individual
panels are connected to a large steel
beam or "strong back" affixed with
lifting eyes on either side.
Migrating fish are directed
through a side channel on one
side of the structure and funneled
between diagonal rows of pickets
(fyke) into a big concrete fish box.
The trapped fish can then be count
ed and studied by Tribal biologists
before being released to continue
their upward migration. The weir
also allows biologists to assess the
health, migration timing and sex
ratio of returning fish.
The weir gate is operated by two
large hydraulic cylinders controlled
by a computer. The hydraulic
system was designed and manu
factured by Applied Industrial
Technologies in close coordination
the Natural Resources staff and the
Tribal engineer to meet the require
ments of the project.
The hydraulic pressures are
continuously monitored by the
computer. The programmable logic
allows for adjustable set points
which trigger operation of the hy
draulic cylinders. If the weir gets
loaded up with leaves and debris,
the pressures will rise. Once the
pressures rise above the set points,
the hydraulic cylinders will release
and the panel will lower, allowing
the debris to clear.
After a preset down time, the hy
draulic cylinders will automatically
retract, the panels will rise and the
system will reset itself. The com
puter will recalibrate the pressures
with each operation to account for
rising or lowering water levels.
Similarly, if the panel is affected
by large debris like a tree stump or
big log, the panels will immediately
lower to prevent the weir
from sustaining damage.
The fish weir was designed
by Tribal Engineer Eric Scott
in collaboration with Kelly
Dirksen, Tribal Fish and
Wildlife coordinator. The
concrete foundations were
constructed by Round Val
ley and Gelco Construction
last fall. The weir panels and
hydraulic cylinders were in
stalled by Sumco Excavating
with help from Natural Re
sources staff. The metal fab
rication was done by Welliver
Metal Products.
While the fish weir itself
is an impressive machine, it
almost pales in comparison to
the spectacular results it has
generated so far this season.
Fish that travel to Agency
Creek must cross Willamette
Falls. The Oregon Department
of Fish and Wildlife operate
a fish ladder at the falls and
count salmon and steelhead as
they travel through. As of Nov.
22, 1,166 coho had crossed the
falls. To date the fish weir has
captured more than 250 coho.
This is an astounding 20 per
cent of all coho in the entire
Willamette Basin in a stream
that makes up far less than 1
percent of the basin.
This is an incredible pro
portion of fish for the ba
sin and reflects well on the
Tribe's management of the
land. Over the last 10 years,
13 culverts were replaced
that posed an obstacle to
fish passage, this resulted in
more than 20 miles of stream
opened for fish use.
More than 160 logs and root
wads were placed in Agency Creek to
improve spawning and rearing habi
tat for fish. Additionally, Natural
Resources staff annually place ap
proximately 4,000 pounds of surplus
salmon carcasses in the stream that
provide a valuable food source for
developing salmon and steelhead.
The current fish count at the weir
is a validation of the tremendous
effort the Tribe has made over the
'V It 4 V f
'it J
Bernards holds a net as Bernard pulls a coho out to be measured and tagged. Below is
a look at most of the fish weir now straddling Agency Creek.
years to manage and improve its
natural resources.
The coho run is probably about
finished for this year. This fish is
generally considered non-native to
the system. The coho are naturally
reproducing in Agency Creek but
they are thought to have originated
from stocking programs discontin
ued in the 1980s.
Steelhead should start arriving at
about the first of the year. Steelhead
l vgirtr. '. t,. , j?h,"nr - jgh:
n w.
ZDim IT, J r 1
are historically native to the stream.
Although many Tribal Elders have
told of successfully fishing for steel
head in the past, the fish is now ex
tremely rare and listed as threatened
by the federal government.
The long-term goal is to see steel
head in equal or greater numbers
than the coho. The fish weir is
one part of a two-part system to
monitor salmon and steelhead in
Agency Creek.
The weir is in operation from
mid-October through April and is
intended to get a count of adult
salmon and steelhead. In February,
a rotary screw trap will be deployed
to capture and get a count of juve
niles migrating out of the system.
This way staff biologists can get a
count of adults and juveniles and
from there they can calculate juve
nile to adult survivorship, a criti
cal bit of information that is key to
developing a reliable management
plan and hopefully someday a fish
able steelhead population on the
Grand Ronde Reservation.
Written by Tribal Fish and Wild
life coordinator Kelly Dirksen and
Tribal Engineer Eric Scott.