Long-Term Structure of Fish Populations in Sagehen Creek, California
- 1 September 1986
- journal article
- research article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 115 (5) , 682-692
- https://doi.org/10.1577/1548-8659(1986)115<682:lsofpi>2.0.co;2
Abstract
Sagehen Creek, California has been a site for long-term study of fish populations since 1952. Samples from permanent study sections were taken in late August 1982 and 1983 in order to determine the current status of species composition and abundance. The first study from 1952 to 1961 used a method that diverted a portion of stream and pumped out remaining pools to census populations at 10 sections over the 21 km of stream. A second study in 1970-1972 used electrofishing over a reach of stream covering the two downstream sections upstream from a newly created reservoir. In 1982, the remaining nine study sections were sampled by electrofishing; in 1983, the most downstream two sections were sampled again. Channel cross sections showed little evidence of scour or fill in the past 4-16 years. In 1982, no fish were collected at the most upstream section. This section formerly (1952-1961) contained an abundant population of brook trout Salvelinus fontinalis. A sequence of drought years probably eliminated the brook trout, but 1982 and 1983 had exceptionally high runoff and several age-classes had recolonized the station by 1985. At the six sections in the middle stream zone, biomasses of brook trout, rainbow trout Salmo gairdneri, brown trout Salmo trutta, and Paiute sculpin Cottus beldingi in 1982 were within the range of fluctuations recorded during 1952-1961. Densities of brook trout and Paiute sculpin were somewhatt lower in 1982 than in the past, probably as a result of the severe flood in the preceding winter. Thus, over most of the stream course, fish populations have been stable or resilient, in spite of years with extremely high and low runoff. In the lower stream zone, above Stampede Reservoir formed in 1969, by contrast, species composition and relative abundance have changed greatly over the years. Immediately after impoundment, Tahoe suckers Catostomus tahoensis and mountain suckers C. platyrhynchus combined went from 18% relative abundance in 1952-1961 to 79% in 1970-1972, but in 1982-1983 they made up about 4% of all fishes. Mountain suckers are now very scarce. Lahontan redsides Richardsonius egregius became rare after impoundment and had resurged (80%) by 1982-1983. Speckled dace Rhinichthys osculus, mountain whitefish Prosopium williamsoni, and brook trout, species that had declined just after impoundment, were not collected in 1982 or 1983 from the lower two sections. The presence and fluctuating level of the reservoir seems to have created conditions that favor some species in the stream but gradually lead to extinction of others in the reach above the reservoir.This publication has 12 references indexed in Scilit:
- Persistence and Structure of the Fish Assemblage in a Small California StreamEcology, 1985
- Replacement of Brook Trout by Brown Trout over 15 Years in a Minnesota Stream: Production and AbundanceTransactions of the American Fisheries Society, 1983
- Stochasticity in Structural and Functional Characteristics of an Indiana Stream Fish Assemblage: A Test of Community TheoryThe American Naturalist, 1982
- Dominance in Fishes: The Relation Between Environment and AbundanceScience, 1982
- Community Organization in Fishes as Indicated by Morphological FeaturesEcology, 1979
- A New Method for Estimating Population Size from Removal DataPublished by JSTOR ,1978
- Habitat Structure and Stream Fish CommunitiesEcology, 1978
- The Quantitative Importance of an Intermittent Stream in the Spawning of Rainbow TroutTransactions of the American Fisheries Society, 1976
- A Long-Term Evaluation of Trout Habitat Development and Its Relation to Improving Management-Related ResearchTransactions of the American Fisheries Society, 1976
- Ionic Composition of Sagehen Creek, California, Following an Adjacent FireEcology, 1966