This article is sponsored by Takshanuk Watershed Council
by Derek Poinsette
In our last Watershed Weekly column, we talked about the life cycle of the Chilkat River king salmon, and recent Alaska Department of Fish and Game management actions that aim to protect the population from extinction and restore it to sustainable levels of production. We also described the salmon life cycle in terms of the four components that are necessary for a healthy salmon run:
1. High quality freshwater spawning habitat,
2. Safe and healthy places to feed as juveniles, both in fresh water and near-shore salt water,
3. Sufficient food and safety in the open ocean to grow to adult spawning age and size,
4. The ability to safely return to natal spawning streams to start the cycle over again.
The ongoing restrictions on harvest are increasing adult salmon survival through stage 4 in the list above. Today, we are going to talk about the importance of stages 1 and 2, freshwater spawning and rearing habitat, specifically right here in the Chilkat River watershed.
King salmon spawn throughout the watershed wherever conditions are appropriate. Compared with the other four species of Pacific salmon, kings prefer larger spawning gravels and steeper gradients. A few streams are particularly favored by spawning kings: Big and Little Boulder creeks on the upper Klehini River, and the Kelsall and Tahini rivers on the upper Chilkat.
Salmon habitat is made from a complex interaction of geology, hydrology, vegetation and the rest of the biological community, and much of the real ecological work is happening underground. This is why activities like road building, or timber cutting, even if they are happening 100 feet away from the stream, can still harm fish. For example, a road cut and fill can alter the flow of a subsurface spring and dry up a salmon spawning bed. Or, a clearcut 300 feet upslope can cause an increase in the flow of surface runoff into a stream and transport fine sediments that smother eggs and permanently destroy spawning habitat. Often we don’t notice these impacts until many years later when someone asks, “Hey, what happened to the salmon that used to spawn in this creek?”
Many of our king spawning streams here in the Chilkat watershed have been altered by industrial development, including road building, timber harvest, and placer mining. There is often some debate over how much, exactly, various activities are impacting fish. But the basic fact is indisputable, and backed by volumes of scientific evidence, that landscape alteration in and around salmon habitat is definitely harmful to fish production and to the long-term sustainability of that fishery. If the disturbance is significant enough it will lead to the extinction, or near-extinction, of the stock. This fact is demonstrated in countless places all over the salmon-producing (or former salmon-producing) parts of the world. There are very few, if any, examples of watersheds that have seen significant development and land alteration, and have also managed to retain strong wild salmon runs.
The other half of this development versus salmon equation is that once salmon habitat is destroyed, it is virtually impossible to reconstruct. In the U.S., we spend millions of dollars every year trying to restore damaged and destroyed salmon habitats, usually to get back just a fraction of the former productivity. Habitat restoration is certainly a worthwhile endeavor, and it benefits multiple species besides just salmon. We shouldn’t fool ourselves, however, into thinking that destroying and then restoring habitat can ever be a wise or an economical way to manage a salmon fishery resource. A recent study showed that after more than 40 years and nine billion dollars spent on salmon recovery in the Columbia River basin, there was no measurable increase at all in the abundance of wild salmon in that watershed1.
Although the Chilkat River watershed is still one of the most productive salmon systems in the world, we nonetheless do have a few examples here of salmon habitat loss due to industrial development. Porcupine Creek was probably a top producer of king salmon back before the placer mining boom a century ago dredged and completely altered that stream. And more recently, we have observed steep declines in king salmon production in the Kelsall River, possibly as a result of the extensive clear-cutting and road building that occurred there in the 1950s through the 80s. The Tahini River is just a few miles from the Kelsall. It was not impacted by timber harvest and is now the number one producer of king salmon in the Chilkat watershed.
So the take home message here is that the only way to maintain big runs of wild salmon is to protect the habitat from alteration and destruction while it is still healthy. And we are fortunate enough here in the Chilkat Valley to have just such a rare and amazing opportunity.
- Jaeger WK, Scheurell. Return(s) on investment: Restoration spending in the Columbia River Basin and increased abundance of salmon and steelhead. Plos One. 2023