Area |
Lower Klamath/Basin-wide |
Topic |
Fish: Basin-wide Summer Steelhead Summary, 1978-87, 1988-97, 1999-02 |
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Caption: Summer steelhead counts in Klamath Basin tributaries showed universal declines from the period 1978-1988 versus 1989-1997, while Trinity sub-basin populations showed an increasing trend. Data for 1997-2002 indicate increases for all basins for which there are data from the 1989-1997 period, but not all Klamath-side tributaries rebounded to levels found in 1978-1988. These data would be consistent with a hypothesis that the mainstem Klamath River was limiting summer steelhead production by limiting survival of older age juveniles or half-pounders during prolonged droughts which occurred in the late 1980's and early 1990's (Kier Assoc., 1999). Population estimates may not be based on complete counts but rather reflect expansions based on counts in index reaches of varying length. Averages were derived by dividing cumulative returns for each period by the number of years surveyed. Not all streams were surveyed in all years. Data provided by California Department of Fish and Game and the U.S. Forest Service.
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