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Stream Temperature Information in KRIS Gualala

KRIS Web Background Pages: Temperature

There is a wealth of temperature data available for the Gualala River, thanks to inexpensive automated temperature sensing probes. These devices make it possible to collect hourly data for months with a limited number of site visits. The large amount of regional temperature information is a powerful tool for analyzing salmonid stream conditions. The Forest Science Project (Lewis, 1999) has provided protocols for water temperature data collection.

The Gualala River Watershed Council (GRWC) and Gualala Redwoods, Inc. (GRI) have collected water temperature data, but only summary findings of GRI were available. These summary data were collected from timber harvest plans (THPs) filed by GRI by staff of the North Coast Regional Water Quality Control Board (NCRWQCB) as part of the North Coast Watershed Assessment (NCWAP). NCRWQCB staff created maximum floating weekly average (MWAT) comparisons in KRIS Gualala and also charts of the absolute maximum by year for each site. The NCWAP thresholds shown on some charts are based on a compendium of literature (EMDS Rating Curve). NCWAP has also revived use of the Fahrenheit scale for interpretation of water temperature and most MWAT and maximum charts are shown in both Celsius and Fahrenheit.

Welsh et al. (2001) and Hines and Ambrose (1998) are the primary "best science" references in KRIS Gualala temperature data interpretations because they reveal relationships between coho salmon and stream temperature known to exist in the nearby Mattole, Ten Mile, Noyo, and Big River basins. The KRIS IFR Team recognizes the coho salmon as the keystone species of aquatic ecosystem recovery in the Gualala River and, therefore, refer to known temperature tolerances of this species whenever appropriate. This approach to analysis to water temperature impairment is patterned after Essig (1998) (see quote). In accordance, 16.8⁰ C (62.3⁰ F) is shown as the reference value for maximum floating weekly average temperature (MWAT). Alternatively, the references of 10⁰ to 15⁰ C are shown on minimum, maximum and average temperature charts because these define the optimal range for salmonid growth as supported by a large body of scientific literature (Brett, 1952; Armor, 1990; McCullough, 1999). See Background page for further discussion.

The following charts and maps are examples from KRIS Gualala and are explained in the adjacent text. For information about the relationship of temperature to riparian condition see the Riparian Information in KRIS Gualala Background page. Hypothesis #4 discusses water temperature as a limiting factor for salmonids in the Gualala basin and shows a wider geographic representation of water temperature problems.

At left is a chart of maximum floating weekly average water temperature at stations in the North Fork Gualala subbasin. The mainstem North Fork Gualala (nf) and the middle reach of Dry Creek (dry12) exceeded 62.2⁰ degrees Fahrenheit (16.8⁰ C) in all years measured (except at site nf251 in 1996) and are therefore unsuitable for coho salmon. All other tributaries [Doty Creek (doty), Little North Fork Gualala (lnf), Robinson Creek (rob) and McGann Gulch (mcg)] may have water temperatures that are not limiting salmonid production Data provided by the Gualala Redwoods Inc.

The map at left shows the North Fork Gualala basin with vegetation and MWAT (F) by location. Vegetation information was derived from satellite imagery by the USFS Spatial Analysis Lab in Sacramento. Maximum floating weekly average water temperature in Fahrenheit are the maximum values for all years measured. The North Fork cools as it moves west off mélange terrain from 72⁰ F to 65⁰ F below Robinson Creek but warms again above its convergence with the Little North Fork. Map provided by the North Coast Regional Water Quality Control Board.

References

Armour, C.L. 1991. Guidance for Evaluating and Recommending Temperature Regime to Protect Fish. Biological Report 90(22). US Fish and Wildlife Service. Ft. Collins, CO. 13 pp.

Brett, J.R. 1952. Temperature tolerance in young Pacific salmon, genus Oncorhynchus. J. Fish. Res. Board of Canada. 9(6):265-323. http://www.humboldt.edu/~fsp/tim/1952article.html

California Resources Agency. In Review. Gualala River Watershed Synthesis. CA Dept. of Fish and Game, State Water Res. Control Bd., CA Dept. of Water Resources, CA Div. on Mines and Geology and CA Dept. of Forestry. Sacramento, CA. Draft released January 16, 2001.

Essig, D. 1998. The Dilemma of Applying Uniform Temperature Criteria in a Diverse Environment: An Issue Analysis. Idaho Division of Environmental Quality Water Quality Assessment and Standards Bureau, Boise, ID. 34p

Hines, D. and J. Ambrose. In review. Evaluation of stream temperatures based on observations of juvenile coho salmon in northern California streams. Draft submitted to North American Journal of Fisheries Management. 21 p.

Lewis, T. 1999 . Regional Stream Temperature Monitoring Protocol. Forest Science Project, Humboldt State University. Arcata, CA. 29 pp.

Lewis, T., D.W. Lamphere, D.R. McCanne, A.S. Webb, J.P. Krieter and W.D. Conroy. 2000. Executive Summary: Regional Assessment of Stream Temperatures Across Northern California and Their Relationship to Various Landscape-Level and Site-Specific Attributes. Forest Science Project. Humboldt State University Foundation, Arcata, CA. 14 p.

McCullough, D. 1999 . A Review and Synthesis of Effects of Alterations to the Water Temperature Regime on Freshwater Life Stages of Salmonids, with Special Reference to Chinook Salmon. Columbia Intertribal Fisheries Commission, Portland, OR. Prepared for the U.S. Environmental Protection Agency Region 10. Published as EPA 910-R-99-010.

Schwind, B. 1999. USFS Thematic Mapper Landsat Vegetation Coverage Background Information. USDA Forest Service. Pacific Southwest Region Remote Sensing Lab. Sacramento, CA.

Welsh, H.H., G.R. Hodgson, M.F. Roche, B.C. Harvey. (2001). Distribution of Juvenile Coho Salmon (Oncorhynchus kisutch) in Relation to Water Temperature in Tributaries of a Northern California Watershed: Determining Management Thresholds for an Impaired Cold-water Adapted Fauna. North American Journal of Fisheries Management, 21:464-470, 2001.