In her series on the legacy of this landmark legislation, VOA environment reporter Rosanne Skirble is examining the continuing debate over the law's impact, and taking a closer look at some of the ongoing efforts to bring endangered species back from the brink. She takes us to a stream in the Pacific Northwest State of Oregon to see how restoration of a critical habitat for endangered salmon involves a mix of scientific fieldwork and politics.
Nestled among willows and pine trees, Knowles Creek flows gently into a tributary of the Siuslaw River on the Central Oregon Coast. Restoration ecologist T.C. Dewberry, wearing a wet suit and snorkel, wades into a shallow pool along the creek to get a closer look at juvenile wild salmon and steelhead.
"We'll stop on this side of the log," he says. "There were 89 Coho and 49 Steelhead on this side of the pool, and the pool is let me see? 15 meters by five meters. So that's a pretty high count."
The Siuslaw River Basin was once one of the most productive aquatic ecosystems in the world. In a good year in the early 20th century the river yielded 500,000 salmon to local fishermen.
But by mid century, salmon harvests from the river had plummeted to just a few thousand fish per year, a casualty of logging, grazing, mining, farming, and irrigation near the sensitive salmon streams. In all, 26 species of Pacific salmon were included on the Endangered Species List.
In his yearly snorkel survey, ecologist T.C. Dewberry counts juvenile fish at Knowles Creek near the headwaters of the Siuslaw.
"We realized that especially when the numbers of fish were low, 80 or 90 percent of the fish may be in 15 or 20 percent of the habitat," he notes. "And so those are the areas that are important because year in and year out those are the areas that produce the most fish. So our approach was to first identify those and find out how to protect those, so at least we are not losing ground. And, that's what happened before. Nobody was paying attention to those critical areas that are producing all the fish. And we were losing those on the landscape. Where now, by identifying them and trying to minimize the risks in just this small little part of the landscape, it gives us a much better chance, we think, of finding a way to actually be successful at restoration."
T.C. Dewberry has snorkeled the entire 804 kilometers of the Siuslaw River and says there has been progress in restoring the waterway to its original state.
Ten years ago this was a bedrock reach (extremely shallow stream). You could roller skate literally on it. Now the gravels (gravel-bottomed stretches of river) are a meter deep through here, and we are looking at a number of really nice pools with real thickets of willow along the edge and a beaver pond right here, and a lot of the water is moving through the gravels and cooling. This is just a real critical area of salmon production right now.
What does it take to restore a salmon stream?
What it takes is to get the soil, water and food resources moving in a natural manner, from the ridge tops, down hill slopes, into streams, channels and then out the estuary. I like to think of it as the digestion metaphor for the landscape. This is the digestive apparatus of the landscape. If the digestion is happening right, then that's what forms the fish habitat and provides the food for the fish and they have what they need. So in our view, it is the recovery of that natural process, that digestive mechanism that is critical.
How do you go about doing that?
Here where the hillsides and tributaries are very steep and we get over 100 inches of rain every year, we get a lot of landslides. Most of the material moves in landslides. And, what is critically important is the trees, especially the large trees because they have the root strength on the hillsides to hold these areas intact. And if you have these big pieces in the material when it sets up in the stream, it can withstand the storm flows and stay in place, and then build these hot spots. It can accumulate the gravels and food resources above them and create these pools like we are in here to create the high quality salmon habitat.
Mr. Dewberry credits progress on the Siuslaw to a partnership that includes an environmental group, a timber company and various government agencies.