Spatial Patterns of Chinook Salmon Spawning in Relation to the Spatial Organization of Riverine Habitats and Core Areas
Total Page:16
File Type:pdf, Size:1020Kb
Spatial Patterns of Chinook Salmon Spawning in Relation to the Spatial Organization of Riverine Habitats and Core Areas Chapter 3 Development of Salmonid Conservation Strategies Phase I, Project No T01426T Presented to: King County Water & Land Resources Division 201 South Jackson Street, Suite 600 Seattle, Washington 98104-3855 Prepared by: Douglas Martin Martin Environmental 2103 North 62nd Street Seattle, Washington 98103 and Lee Benda Earth Systems Institute 3040 NW 57th Street Seattle, Washington 98107 February 6, 2004 TABLE OF CONTENTS Introduction ...................................................................................................................1 Materials and Methods.................................................................................................. 3 Study Rivers.............................................................................................................................. 3 Riverine Physical Features........................................................................................................ 5 Chinook Salmon Redd Distribution and Abundance................................................................ 5 Data..................................................................................................................................... 5 Analysis............................................................................................................................... 6 Results ........................................................................................................................... 8 Identifying the Spatial Structure of Riverine Habitats.............................................................. 8 Lower Snoqualmie River .................................................................................................... 8 General River Basin Characteristics ............................................................................. 8 Valley Segment Characteristics .................................................................................... 8 Network and Tributary Junction Characteristics .......................................................... 8 Other Data................................................................................................................... 13 Lower Skykomish River ................................................................................................... 15 General River Basin Characteristics ........................................................................... 15 Valley Segment Characteristics .................................................................................. 16 Network and Tributary Junction Characteristics ........................................................ 17 Other Data................................................................................................................... 18 Lower Green River ........................................................................................................... 18 General River Basin Characteristics ........................................................................... 18 Valley Segment Characteristics .................................................................................. 19 Network and Tributary Junction Characteristics ........................................................ 19 Other Data................................................................................................................... 20 Lower Cedar River............................................................................................................ 21 General River Basin Characteristics ........................................................................... 21 Valley Segment Characteristics .................................................................................. 22 Network and Tributary Junction Characteristics ........................................................ 22 Other Data................................................................................................................... 23 Predicted Structure of Spawning Chinook Habitat: Similarities and Differences Across the Four River Basins ..................................................................................... 24 Identifying the Temporal Structure of Riverine Habitats ....................................................... 25 Chinook Salmon Spatial Patterns of Spawning and Association with Riverine Features ...... 26 Distribution of Spawning Habitats Compared to Predictions................................................. 40 Other Factors Potentially Influencing Chinook Salmon Spatial Patterns of Spawning.......... 41 Predicting Core Areas for Chinook Salmon in the Upper Green River.................................. 42 References................................................................................................................... 45 Appendix—Annual Peak Counts of Chinook Salmon Redds by Survey Segment LIST OF FIGURES Figure 1. Location of study reaches and Chinook salmon distribution in the Skykomish, Snoqualmie, Cedar, and Green rivers. Figure 2. Schematic illustrating where measurements were taken to determine distance from the center of each survey segment to the nearest river feature. Figure 3. Snoqualmie location map. Figure 4. Snoqualmie gradient map. Figure 5. Snoqualmie valley segment and confluence map. Figure 6. Longitudinal plots of valley widths and channel elevation for the four study rivers. Figure 7. Surface sediment size in Snoqualmie River (from Booth et al. 1991). Figure 8. Skykomish location map. Figure 9. Skykomish gradient map. Figure 10. Skykomish valley segment and confluence map. Figure 11. Green River location map. Figure 12. Green River gradient map. Figure 13. Green River valley segment and confluence map. Figure 14. Cedar River location map. Figure 15. Cedar River gradient map. Figure 16. Cedar River valley segment and confluence map. Figure 17. Chinook salmon redd distribution in the Skykomish River: a) annual standardized redd densities, and b) trend for geometric mean (GM) of standardized redd densities. Data for (a) are from all years with six or more survey segments, and data for (b) are for all years in which data were collected for the segments shown during the period 1956 to 1998 (N ranges from 11 to 36). All values are plotted at the midpoint of segments. Figure 18. Chinook salmon redd distribution in the Snoqualmie River: a) annual standardized redd densities, and b) trend for geometric mean (GM) of standardized redd densities. Data are for all years with four survey segments (N = 12) and values are plotted at the midpoint of segments. LIST OF FIGURES (continued) Figure 19. Chinook salmon redd distribution in the Cedar River: a) annual standardized redd densities, and b) trend for geometric mean (GM) of standardized redd densities for all years (N = 4). Data are plotted at the midpoint of segments. Figure 20. Chinook salmon redd distribution in the Green River: a) annual standardized redd densities, and b) trend for geometric mean (GM) of standardized redd densities for all years (N = 4). Data are plotted at the midpoint of segments. Figure 21. Peak annual redd counts for Chinook salmon in the Skykomish, Snoqualmie, Cedar, and Green Rivers. Figure 22. Chinook salmon standardized redd density as a function of distance to the nearest river feature for all study rivers. Plot based on all tributary and river feature data. Figure 23. Chinook salmon standardized redd density as a function of distance to nearest river feature in the Skykomish River. Plot based on all data. Figure 24. Chinook salmon standardized redd density as a function of distance to nearest river feature in the Green River. Plot based on all data. Figure 25. Chinook salmon standardized redd density as a function of distance to nearest river feature in the Snoqualmie River. Plot (a) based on all data and plot (b) excludes tributaries with a subbasin size ratio < 5%. Figure 26. Chinook salmon standardized redd density as a function of distance to nearest river feature in the Cedar River. Plot (a) based on all data and plot (b) excludes all tributary features. Figure 27. Chinook salmon standardized redd density as a function of distance to the nearest river feature for three study rivers with large tributaries. Plot (a) based on all data excluding tributaries with a subbasin size ratio < 5% and excluding the Cedar River. Plot (b) based on same data as plot (a) but also excludes data from segments adjacent to fish barriers. Figure 28. Upper Green River; a) location of significant confluences, canyon mouths, and landslides, and b) predicted core areas for Chinook salmon spawning. LIST OF TABLES Table 1. Characteristics of the redd survey data used in this analysis. Table 2. Location of river features in the four study rivers, including tributary basin size, size ratio, and effect size. The * indicates P values associated with segments that have high redd density. Table 3. Summary statistics of standardized redd density by river feature distance category for the ANOVA test groups. Table 4. Analysis of variance test results of differences in Rankit-transformed standardized redd density among river feature distance categories. Table 5. Results of Tukey multiple comparisons tests of Rankit-transformed standardized redd densities for three different river feature distance categories and two test groups. Table 6. Chinook salmon spawning patch location, length, and inter-patch distance. INTRODUCTION In Chapter 1