To keep every cog and wheel is the first precaution of intelligent tinkering.
— Round River: From the Journals of Aldo Leopold
It’s not exactly a revolution, but still it won’t be televised, and so that’s why I’m telling you about it here. As you read this, wild Chinook salmon are nosing their way upstream in Alaska’s salmon rivers.
No, it’s not a revolution, but it is remarkable for this reason alone: Even in a changing world, it still happens. This year, biologists expect more than 180 million wild salmon to return to Alaska’s rivers.
A few weeks ago, my wife and I joined friends to paddle 40 miles on one of these rivers. In Alaska, a May outing promises weather that hearkens back to winter: indeed, I felt a chill when we saw fresh snow in the peaks of the Chugach Mountains on the damp morning we set out.
The rain soon relented, however, and we watched spring erupt: new birch leaves speckled the forest a tender green and the first butterfly of the year — a spring azure — crossed our path in the woods. We watched a porcupine straddle an alder along the bank. Off in the woods somewhere, we could hear a single ruffed grouse drumming in spring courtship. We plucked fiddleheads for our skillet. Near our camp, I held a wood frog in my cupped hands.
All of this was a warm-up act for the main stage: the return of the Chinook salmon. We saw only tiny salmon fry in the river shallows, but the wealth of the salmon was all around us. Biologists tell us that salmon returning from the sea transport the basic nutrient building blocks of life — nitrogen, calcium and phosphorous are among them — for the river and the entire watershed.
The fine threads of a salmon stream food web reach far — to the very species we encountered in our canoe trip. In fact, more than three dozen species of vertebrates — bears, wolves, mink and others — feed on the annual smorgasbord of salmon, their eggs and spawned-out carcasses. The scientific literature shows that up to 40 percent of the nitrogen in a riparian forest can be traced back to wild salmon.
Much of Alaska’s salmon habitat remains intact and healthy, but this natural spectacle I witnessed is happening in a region facing the threats that decimated salmon populations in the lower 48. Even far-flung Alaska isn’t immune to the pressures of urban sprawl and invasive species.
The Nature Conservancy in Alaska is at work in the upper reaches of the Little Susitna River watershed to ensure that spawning salmon and their young have free, unhindered access to the entire reach of the river’s tributaries. On one tributary named Colter Creek, the Conservancy and several partners last summer replaced culverts at road-crossings that blocked safe passage for young wild salmon. Teenagers and Girl Scouts pulled on their rubber boots and pitched in, too, by replanting native streamside plants and charting the return of wild salmon to these waters. This summer, the Conservancy is restoring safe passage on two more tributaries on the Little Susitna River.
This is vital work. In much of the world, wild salmon haven’t fared so well. Europe’s wild salmon stocks have mostly disappeared and in the lower 48, more than a dozen salmon runs are now listed under the Endangered Species Act. In the Northwest’s Columbia River, for instance, just four percent of the wild salmon run still remains.
In Alaska — and this strikes many as astonishing — most wild salmon runs are still healthy. Not simply healthy, but still healthy. For now. If, as Aldo Leopold tells us, an intelligent tinkerer saves every cog and wheel, we would do well to heed his advice in Alaska’s salmon systems — mighty biological engines that need all their pieces. And in the Little Susitna watershed, where the Conservancy is restoring the important pieces we haven’t kept, we’re preparing the way for the salmon returning home about right…now.
(Image 1: By restoring fish passage on Little Susitna River tributaries, the Conservancy and its partners are ensuring that young salmon have access to vital rearing habitat. Credit: Bridget Besaw. Image 2: Little Susitna River, May 2009. Credit: Dustin Solberg/TNC. )