Sometimes to think like a fish, you have to swim with the fish

And that is just what salmon restoration expert, Charley Dewberry did. I had never heard of Charley until recently when Karl Mueller of the Oregon Fly Fishing Blog wrote a piece about a salmon restoration presentation Charley put on. It is amazing, here it is:

‘The good news is that the fish are still here.  Despite our best efforts for the past hundred years, they are still around.”   Charley Dewberry, March 2009.

map produced by ecotrust

map produced by ecotrust

But as the graphic shows, they are threatened.  Our task is restoring salmon and their watersheds and to do that we need to know what the habitat and watershed  looked like and how it functioned in its undisturbed state.  This has been a large part of Dewberry’s life’s work.

According to Charley, large woody debris placement projects as they were and still are (to a certain extent) being conducted are not “restoration.”  They are  “band-aids”, or ” random acts of kindness” that have their place  and will boost numbers in the short run  but will never achieve true restoration.

When Charley’s work began, Forest Service restoration planning consisted of clear-cutting and placing a large woody debris jam where convenient.  This didn’t bring salmon back, that much was clear.  The question was, why not?

To answer that question, Charley asked the fish.  As architect of the Knowles Creek restoration project, he snorkeled the entire length of Knowles Creek in the Siuslaw basin and what he found was something of a surprise: three fourths of the salmonid smolts were in one beaver pond.  This area obviously was highly productive.  He also noticed that in years when smolts were relatively abundant they were small; when they were scarce, they were large.  It doesn’t take a biology degree to riddle that one: they are food limited.

Charley realized that the whole watershed is not created equal for salmonids.  Instead, the entire Knowles Creek basin contains about 20 “flats.”  If the creek near the flat was being slowed, clogged with the boulders and enormous trees from a debris flow, this would create a slower water habitat ideal for rearing salmon smolts.  These areas, where flats coincided with log/debris jams are described quite aptly by Charley as “pearls on a string.”   The system was never static . . . the “pearls” moved on the string but the constant was that some of these these high value habitats, the flats, were life supporting pearls . . . .

The lesson?  Large woody debris projects need to be strategically placed in areas with high intrinsic potential, not where a  road is conveniently near the creek, or underneath some timber unit where you have some spruce logs stacked.   Another thing Charley mentioned is the types of trees that were present in these debris flows can’t be helicoptered in, can’t be truly replicated by anything but time and natural occurrence, they need to grow again.

These were true Oregon Coast Range giants, the backbone of the historic log jams  that formed beneath the flats and created the conditions that made huge runs of adult salmon possible:  remaining in place until perhaps another catastrophic storm event; decomposing over a period of twenty or more years; collecting the leaves, carcasses and debris that form the base of the food chain; and, retaining the gravel that adults need to spawn.  They were trees like this and lots of them:

normal sized sitka spruce

normal sized sitka spruce

Now, what comes sliding down the hill is smaller second or third growth and associated slash and debris that holds for at most a couple minutes temporarily damming the creek until the tremendous hydraulic power of the water blows it out, sending sediment downstream constantly and scouring the creek bed–more similar to splash damming during early log drives than  historic conditions.

The action, as Charley sees it, is as much on the slopes as it is in the riparian area.  The areas where historic debris slides occurred, (and these are a limited number of areas) need to be protected from harvest so that enormous trees may again grow and slide into the watershed.

We’ve been thinking too small, according to Charley, focusing our restoration efforts on the reach scale rather than looking at the entire watershed.  There are three things that need to happen according to Dewberry in order to see meaningful “restoration.”  In his view, all of these things have to be done to see fish populations recover:

  • Protect highly functioning areas and areas with high intrinsic potential to  contribute to fish productivity.

This means protecting the upslope areas that  are likely to contribute large woody debris to the system naturally, the debris fans.  This also means protecting the riparian areas.  This also means protecting or restoring the flats.

  • Stormproof the roads.

The Oregon Coast range is built out with many roads.  Where streams cross these roads, the culverts need to be designed for a one hundred year flood event.  If the culvert does fail, it should be designed to fail at the crossing.  It is much more destructive for the water to flow in the road ditch for a couple hundred yards and then blow out the road flowing downhill through an area that hasn’t been previously eroded in that manner.

  • Re-establish mixed species riparian areas.

Currently riparian areas are alder dominated and restoration efforts often focus on planting alder.  Alder is important.  It is a nitrogen fixer in a nitrogen depleted system and it is also “the fastest leaf in the west.”  Alder drops its leaves first and they are the first to be eaten by the stoneflies that are the most important aquatic macro-invertebrate in the Coast Range watersheds.  But, alder leaves are also the first to decompose.  Right now, in February/March everything (the bugs anyway) is eating maple leaves.  It isn’t as high quality food, but it lasts.  Currently, maple is in short supply.  Without food there are no bugs.  Without bugs there are no salmon.

For those of us that care about salmon restoration, the task before us is huge and daunting.  But we are very lucky in that the Siuslaw, which is in our backyard has some of the best potential for recovery of any river in the United States.  The stream used to (and still does at times) produce huge numbers of fish, much of the basin is in public ownership, Florence, at the mouth, is the biggest town in the watershed, and with the exception of industrial forestry, there is really no industry in the basin.  According to Charley, if we can’t do it on the Siuslaw, we can’t do it anywhere.

I believe that with hard work, the Siuslaw can recover. If you think otherwise, it might be worth remembering that despite our best efforts, the fish are still here.–KM

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~ by theriverwrites on March 25, 2009.

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