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Faith: We're down on the banks of the
Willamette River. Over the last couple
of days we've had quite a bit of rain
and flooding that went on in the
Portland area, so the stage of the
river is quite high and it backs up
into the mouth of the Tryon Creek here.
They have a lot of wood that has been
placed here as part of the
rehabilitation project. What's the
importance of all the wood that we've
been seeing in the area?
Jennifer: The Pacific Northwest is
characterized by ancient forests with
giant logs, and when these things would
blow down into a stream, they could
take hundreds of years of being in that
stream for macroinvertebrates to attach
onto and just fish to hide underneath.
And as those logs move through the
system they also got hung up on
riverbanks like this one here. So, as
we've been logging out our beautiful
old growth forests we've just really
lost that habitat element. And so what
we do is we just try to restore those
pieces and give the fish a place to
hide out. We really like to use the
root wods that you see here because
they're all messy and a fish could dart
in there and hideout. A bigger fish
might not be able to get in there after them.
Faith: With the Tryon Creek, too, it's
a side channel of the Willamette and so
it also had some fish passage issues.
What were some of the problems with that?
Matt: One of the problems with fish
passage was that at lower flows the
culvert under the highway just about
1,000 feet up would become perched and
water would spill down making it
difficult for fish to get into. And so
one of the things we did in the early
phase of the project was to raise the
channel bed up about two feet so that
the fish could at least access that
culvert during those conditions.
Faith: The mouth area – really
important for a lot of fish species
that are characteristic of the large
rivers here too. What are some of those species?
Tim: Yeah, so a number of the
tributaries, the Tryon included, come
in, and you mentioned that the heavy
rains have created some backwater, and
actually the tidal cycle from the ocean
can be influenced all the way up –
Faith: All the way up to here, huh?
Tim: – to here as well. And so there
are a number of listed species that
pass this area in the Willamette. There
are Coho Salmon, there're Steelhead,
there're Snook, there're Pacific
Lamprey, which are not listed under the
Endangered Species Act, but we know
adults pass here as well as juvenile
and larval forms rear here, Western
Brook Lamprey also rear in the main
stem. All of those species use the
mouths of the tributaries, including
potentially this area of Tyron, for
some rearing opportunity.
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