The Fish and the Watershed

I am sure most of you have heard tales of the vast quantities of fish that historically spawned in our coastal rivers. The legend claims that "the fish were so plentiful you could walk across the rivers on their backs" - a slippery proposition at best. As recently as 20 years ago numerous salmon and steelhead trout spawned in Salmon Creek. Now it is rare to see a steelhead, and it has been several years since a salmon has been identi-fied. Populations are down to the point of being listed by the government as threatened or en-dangered from central California all the way up the coast. Especially in the Salmon Creek watershed, I wanted to know what happened to the fish. Why did they leave? And what, if anything, can we do to convince them to return? To find answers to these rather nebulous questions I spoke with a number of people in differ-ent areas of environmental studies, whom I would like to thank. These included most notably Dr. Michael Banks, a geneticist with UC Davis doing research at the Bodega Marine Lab on salmonid populations; Katie Etienne and Jim Tischler, long time activists with Trout Unlimited, with a particularl interest in Salmon Creek; Joe Pozzi, with the Gold Ridge Resource Conservation District (GRRCD); Liza Prunuske, a founder of Prunuske Chatham, Inc., an environmental restoration company; and Linda Esposito, a botanist who is studying, among other things, the native plant populations of lower Salmon Creek. I am particularly grateful to Dr.Banks who generously agreed to discuss his work and the watershed. There is general agreement on a few basic points. When asked whether we might be observing the results of a natural cycle, Dr. Banks replied simply, "who knows?". Natural cycles can cover long periods of time and there is not enough data to know what's going on long term. A hundred year flood, for example, could so change a spawning stream that the fish would reject it. We do know, however, what conditions the fish like for spawning. They like shallow, gravelly beds, a gentle flow of pure water, and plenty of shade. In fact, if the whole creek isn't shaded enough the water will heat up to the point that the fish will reject it. The worst enemies of these desirable conditions are siltation, which buries the gravel beds, effectively destroying the spawning grounds; pollution, making the water too distasteful to consider; low water flow due to drought or excessive water use upstream; and a lack of riparian, shade-giving vegetation. These conditions are interrelated. Siltation is caused mainly by erosion due to a lack of roots to hold the soil.. Low water flow concentrates pollutants, and allows silt to build up. Overhanging riparian growth not only keeps the water cool but also is a barrier to large animals, keeping them from erroding the banks. Without sufficient water, the riparian cover won't grow. In lower Salmon Creek siltation has made the creek bed shallower, slowing the flow and allowing more siltation, a real catch 22. Clearly a two-pronged solution is needed here: increase the flow and stabilize the sources of erosion. At present a few juvenile fish survive in the side creeks. There are more young in the creeks closer to the ocean than in the upstream tributaries. Hatchlings remain in creeks one to three years before swimming out to sea in the high water of Spring. They return, usually to their native creeks, after four or five years. Dr. Banks reports seeing fry (about 1" long) in upper Nolan Creek (along Joy Rd.) and in upper Salmon Creek (above the middle school). They are too small to tell if they are steelhead or salmon, but it is highly unlikely they are salmon. Nonetheless it is a very hopeful sign to find fry this far from the ocean. In mid-September I observed three different sizes of juveniles in Fay Creek. These, according to Banks, represent three different runs, whose survival is also a good sign.

"What about simply stocking the creeks with fry from the fish hatchery until enough come back to reestablish the runs", I asked innocently. Again there was general agreement: this would be a genetic disaster. The viability of a population depends on genetic diversity. Banks' work has allowed him to analyse the genetic differences between native populations in such detail that he can distinguish not only stream-specific groups, but the different annual runs within a stream. By isolating, quantifying and comparing parts of the genome known to mutate easily, called micro-satellites, Banks and his co-workers can determine the diversity of a group. They have been able to demonstrate that the wild populations are more diverse than hatchery fish, as well as being stream-specific. To introduce foreign genes into this delicately balanced situation could destroy a local run forever, as well as weaken the wild gene pool in general. A gene bank has been established at the Bodega Marine Lab, partly to guard against the extinction of distinct groups. It can be used to strengthen existing groups but would only be used to restock a stream if it was clear the native run had disappeared, and Banks is not yet convinced this is the case in Salmon Creek. Chinook like long runs such as the Sacramento and Russian Rivers, but Coho prefer short runs. Coho survival is therefore dependent on the health of small coastal watersheds such as ours. No Coho have been trapped recently in Salmon Creek. However, Coho are showing up in Laganitas Creek in Marin, where in the last few years extensive restoration work has been done under the direction of Prunuske Chatham Inc. Since Coho sometimes like to explore different creeks at spawning time instead of just making a beeline for their home creek it is possible that the Laganitas Coho are effectively the same as those from Salmon Creek. If conditions in Salmon Creek inprove enough, runs of Coho may return. Luckily, the Salmon Creek watershed is in exceptionally good condition. Circuit Rider Productions recognized this in a 1967 survey, and according to GRRCD it is still true today. Salmon Creek has become recognized as a good example despite the loss of our fish. But this is no reason for complacency. It is time to ask "what can we do to help restore our spawning grounds and restore our fishery?". Several of the people I talked to observed that the greatest impact on the watershed in the last 15 years comes from the increase in water use due to an expanding population. Every home and ranch puts a small drain on all our resources It's important to remember that some water company does not pipe our water in from somewhere else. All the water we use is drawn out of the watershed and depletes the potential flow into the creeks, so the most important thing is ...don't waste water! Just paying attention to simple things like not letting the water run while brushing your teeth, and using your wash water to water your plants can make a tremendous difference if we do it together. The kids can get involved too. They could make a game of seeing how many ways they can find to save water and estimating how much is being saved (not bathing is not an option). Erosion around the home is another area where we can make a difference. When it rains, see if your down spouts are causing erosion, and check the flow off your driveway. Paved and improperly graded roads, especially in the hills, concentrate runoff and funnel silt into the creeks. If you have a serious erosion problem, or own part of a creek and would like help with riparian planting, or fencing, please call us. There are several government agencies that can provide up to 90% of the cost of materials, and we have volunteers who will help with the labor. Now supposing you have become the best watershed steward in the world and your place is in great shape. What's the best way to make sure it will stay that way after that inevitable time in the future when you no longer own it? Here's where a local land trust can really be of service. We can help you write a conservation or agricultural easement for your property that will keep it the way you want it, and may provide a nice tax break as well. Just give us a call and we will be happy to send you information on how easements work. By working together we can look forward to a healthier, happier watershed. And check the creeks this winter - there may be a Coho in your future!

Salmon Creek Watershed