Conservation by Ron Forbes
"Today she met me at the door, said I would have to choose, if I picked up that fishing pole today, she'd be packing her all things and she'd be gone by noon… Well I'm going to miss her when I get home tonight. Right now I'm sitting on this lake shore, and I'm sitting in the sun! I'm sure it will hit me when I walk through that door tonight. Yeah, I’m going to miss her. Oh lookie there, I got a bite!"
Salmon make the vines grow!
We are getting to that time of year when the chinook salmon and steelhead make their annual migration up the Mokelumne River. For the past few years I have made bi-weekly calls to the Mokelumne Fish Hatchery to find out how many fish have passed the fish counter at the Woodbridge Irrigation District and how many fish have been harvested for their eggs. On the first day of the new year, the Mokelumne opens again to fishing and the Delta Fly Fishers host our annual party open to all to celebrate a new year of fishing on the river and a look forward to a wet winter and a great coming trout season in the Sierras. At the end of the salmon- steelhead run, we look at this as the end of one cycle and the start of another. However, it is, in reality, the continuing of the gift the salmon give us.
Drs. Joe Merz and Peter Moyle wrote a scientific article in the Ecological Society of America entitled, "Salmon ,Wildlife and Wine: Marine-Derived Nutrients in Human Dominated Eco- Systems of Central California." Many members of our club will remember working with Joe Merz restoring cottonwoods on Murphy Creek, a tributary of the Mokelumne, when he was the Supervising Biologist for East Bay Municipal Utility District. Peter Moyle is a well-known aquatic biologist at the University of California at Davis. The paper describes how salmon continue to have a profound effect on both the Mokelumne and Calaveras Rivers long after they have spawned and died.
This salmon carcass will feed bacteria, insects, small animals and grape vines!
Since salmon are residents of two eco-systems, both fresh and salt water, they are ex-posed to two different sources of nutrients. While in the ocean, salmon are major predators and exposed to variants of nutrients that are not found in great amounts in fresh water. And since they are migratory, they are a major source of nutrient
transport between the two eco-systems. In the more pristine wa-ters of the rivers of Washington, Oregon, and northern California, the nutrient transfer is important to maintain both the riparian and land ecosystems. However, in central California along the Mokelumne and to a lesser de-gree, the Calaveras, these nutri-ents also play very important part in the wine industry.
Merz and Moyle studied the ratio of stable isotopes of both nitrogen (N) and carbon (C) to determine the origins of the salmon's nutrients. In a salmon's tissue, there are more of the heavier isotopes of N and C (15N and 13C). This is referred to as marine-derived nitrogen (MDN). The lighter isotopes of both N and C are found more in fresh water. By observing the ratio of heavy/light isotopes, they could determine the MDN far from the riparian systems.
"The authors estimate that the vegetation and wine grapes adjacent to the Mokelumne River get between 18-25% of their nutrient from the salmon."
When the salmon spawn, they release nutrients in a variety of ways. First through metabolism, the release of their eggs, the consumption of their flesh by predators or scavengers, and in the decomposition of their carcasses. The salmon are eaten or are decomposed by everything from bears to bacteria. They are an important source of MDN in both the riparian eco-system but also in the terrestrial environment next to the streams or rivers where they spawn. The authors estimate that the vegetation and wine grapes adjacent to the Mokelumne River get between 18-25% of their nutrient from the salmon. The MDN have been found several hundred yards inland from the river
The authors observed that 14 vertebrate species feed on the salmon carcasses along the Mokelumne below Camanche dam. Even herbivores such as western gray squirrels and mule deer have been seen feeding on salmon carcasses. More tradition-al scavengers include turkey vultures, opossums, raccoons, along with domestic dogs and cats. The study shows that even thought the Mokelumne is a highly altered river for agriculture and flood control, the salmon continue pro-vide huge effects on both plant and wildlife production and are of substantial economic value to the vineyards along the river. Recent estimates of the salmon's value to the state of California has been put at $1.3 billon. This estimate is based on commercial and sport fishing and related business.
At this point the finical estimate does not include the salmon's importance to agriculture next to rivers and streams which are spawning areas. This is another, of many good reasons, to continue to fight for the survival of our salmon.
A few words of thanks....
I would like to thank the members of our club who took their time to be an important part of Stockton's Second Annual Steel-head Festival. The club was the outstanding group in the Environmental, Conservation/Fisheries section. With four tables, fish carving, fly tying and casting we stood out once again.
At the club meeting before the festival there were only 27 members in attendance. But when I passed a sign-up sheet , 17 people had signed up to help. On the day of the festival, 19 to 20 people were on hand to help! Immediately after the event, Jerry Neuburger wrote an outstanding article, with pictures, on our website.
For all of you who worked so hard to make to make the Steelhead Festival a success and Delta FF participation so outstanding.....