TRIBAL PROGRAM NEWS
The Estuary, The Hatchery, and More
by Stan van de Wetering
Estuary Project
We spent most of September
collecting depth, salinity, and temperature
data for Siletz Bay. Using a Global
Positioning System computer, we measured
elevations at several hundred locations in
the bay. These data will be used to produce
a map describing water depths at high and
low tides across the bay and throughout
the marshes.
Our main use for these data is to help
us decide where to look for juvenile salmon
in the spring when we are monitoring for
habitat use. We also hope to use the
elevation data to look at the effects of
sediment transport on the shape and depth
of the bay.
Lamprey Project
During August, I spent a week on
Tenmile Creek collecting eel smolts. This
fall we will look at the fat content of these
little guys to prepare ourselves for a small
experiment next summer.
In past articles, we have covered our
interest in increases in stream temperatures
and previously described an experiment
where we examined the maximum water
temperature baby eels could tolerate before
dying. It was surprisingly high (80 degrees).
Smolting eels live off of stored fats for
seven months prior to entering the ocean.
Most animals are known to respond to
increases in temperature with an increased
metabolic rate, which means more energy
is burned. For eel smolts, this means
stored fats are burned as stream
temperatures increase.
At least that is the theory behind the
question we will be asking. We will measure
the total fat content of the eels sampled in
the summer of 2000. From these data, we
will determine mean fat content and the
range of fat values, which will tell us how
many fish total we will need next year.
Next year, we will put three groups of
eels in each of three unique high-
temperature tanks for 60 days, then
measure the differences in mean fat content
between the three groups. We will then
compare our current stream temperatures
with those used during the experiment and
suggest whether a potential negative effect
6
Frank Simmons and Miles van de Wetering survey the area
around the new hatchery pond.
is present or not. That is, are current high
stream temperatures affecting eel smolt
survival during the summer.
Hatchery Project
As described in our last update, we
had plans for three projects on the hatchery
property this summer/fall. The first, digging
a new earthen pond where the old raceways
were buried, is now complete. Quinn Murk
of Total Tree Logging was our contractor for
this work.
Quinn spent a week removing the old
concrete structures, pipes, wires, and
various other types of garbage from the site.
It was quite a mess and we spent much
more time cleaning out refuse than digging
the actual new pond. We ended up storing
a fair amount of concrete on the corner at
the quarry site. We hope to find a grant this
year to move the refuse off the hatchery
property. Quinn did a great job and put in
several hours of volunteer time.
The second project was the adult fish
trap. We contracted the work with Marv
Willey and he too did a great job. We have
not set a date for building the pole barn,
which will provide shelter for many uses,
but we expect it to be done by Christmas.
We will use our 3K charitable fund grant to
finish the water, sewer, and electric setup
Mike Elkins helps paint at the hatchery.
this month, which will allow a camp host to
move in.
As most of you know, the hatchery site
is not always the best choice for harvesting
bright fish unless the rains hit at just the
right time. I’m told that in the past 10 years
or more, this site has not produced much
of anything. This looks like an improvement
on the recent past and if we get lucky and
see a 1 percent survival rate for adult coho,
we should have between 350 and 450 coho
adults returning to the Rock Creek system.
(See Hatchery on page 7)