Nearshore Habitat Use by Juvenile Chinook Salmon in Lentic ...

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Tributary mouths appear to be especially valuable habitat for Chinook salmon during high streamflow conditions. Chinook salmon appear to respond both functionally (change in diet) and numerically (change in abundance) to increased streamflow. At all three tributary mouths, the diet breadth was higher at high streamflow than at base streamflow conditions. A large percentage of the diet during high streamflow conditions consisted of benthic prey such as chironomid larvae and oligochaetes. These prey items may become more available due to streambed scour and prey are displaced downstream. At May Creek, we found the abundance of Chinook salmon can increase during a high flow event. An increase in prey availability as well as flow may attract Chinook salmon and other salmonids such as cutthroat trout. At Taylor Creek, we were unable to demonstrate an increase in Chinook salmon abundance due to an increase in streamflow. Taylor Creek is much smaller than May Creek and thus the amount of prey and attraction flow is most likely less. Also, May Creek may have been easier to sample with a small beach seine than Taylor Creek because the delta of May Creek is confined between two riprap banks and fish may be easily encircled with a beach seine. 53
CHAPTER 6. USE OF NONNATAL TRIBUTARIES Introduction and Methods The lower reaches of several nonnatal tributaries were surveyed in 2002. Juvenile Chinook salmon commonly used the tributary delta areas within the lake but they were only found in the lotic environments of a few tributaries (Tabor et al. 2004b). Nonnatal tributaries that had a high abundance of juvenile Chinook salmon were small- to mediumsized streams, which had a low gradient and were close to the mouth of the natal system. In 2003 and 2004, we surveyed Johns Creek and Culvert Creek to collect additional information on the use of nonnatal tributaries. Johns Creek was surveyed to determine if the tributary is used extensively from year to year and to collect some information on Chinook salmon habitat use that could be used to design restoration projects of other nonnatal tributaries. For example, the City of Seattle has proposed to daylight the mouth and lower 100 m of Mapes Creek (currently in a culvert and enters the lake a few meters below the lake surface), yet little information is available on what type of habitat conditions would be best for Chinook salmon. In 2004, we also surveyed Culvert Creek because it is also a small, low-gradient creek that is close to the mouth of the Cedar River; however, the creek is located entirely within a culvert. The creek is located approximately 0.65 km north of Johns Creek. Johns Creek.—Johns Creek is located in Gene Coulon Park in the southeast corner of Lake Washington, 1.5 km from the mouth of the Cedar River. Typical winter streamflow is about 0.8 cfs (Tabor et al. 2004b). Juvenile Chinook salmon use the lower 460 m of the stream (Tabor et al. 2004b). Upstream of this, there are two equal-sized streams that appear to be completely in culverts. In 2003 and 2004, we repeatedly surveyed the same 260-m long reach that was surveyed in 2002 (Tabor et al. 2004b). The downstream end of the study reach was the lake. There was no developed delta unlike other tributaries to Lake Washington. The upstream end was a large culvert near the entrance to Gene Coulon Park. The study reach was delineated into habitat units, which were either classified as a convergence pool, scour pool, glide, or riffle. The convergence pool was the lower 61 to 136 m of the index reach that the water level was directly influenced by the lake level (Figure 31). As the lake rose from February to June, the convergence pool grew progressively larger. Scour pools were other pools upstream of the convergence pool that had a maximum depth > 0.35 m. Glides or shallow pools were other slow water habitats that had a maximum depth < 0.35 m (Figure 31). The maximum pool depth of 0.35 m was adapted from Timber-Fish-Wildlife (TFW) stream ambient monitoring methodology (Pleus et al. 1999). For a stream the size of Johns Creek (5- to- 10-m bankfull stream width), the authors recommended pools have a residual pool depth of 0.25 m (residual pool depth = max. pool depth–outlet pool depth). Because the outlet depth of pools was approximately 0.1 m deep, we used a maximum pool depth as > 0.35 m. Riffles were 54
Page 1 and 2:
U.S. Fish and IU.S. Wildlife FishSe
Page 3 and 4:
SUMMARY In 2003 and 2004, we contin
Page 5 and 6:
An overhanging vegetation/small woo
Page 7 and 8:
Table of Contents Page SUMMARY ....
Page 9 and 10:
List of Figures Figure Page FIGURE
Page 11 and 12:
FIGURE 37.—Water column depth (m)
Page 13 and 14: The major tributary to Lake Washing
Page 15 and 16: Fry emerge from their redds from Ja
Page 17 and 18: FIGURE 2.—Location of index sites
Page 19 and 20: most dates (Figure 4). Unlike 2002,
Page 21 and 22: Chinook/m 2 1 0.8 0.6 0.4 0.2 0 Wes
Page 23 and 24: 0.3 Mercer Island Chinook/m 2 0.2 0
Page 25 and 26: particularly valuable. Shoreline im
Page 27 and 28: FIGURE 8.—Map of south Lake Washi
Page 29 and 30: FIGURE 10—Map of south Lake Washi
Page 31 and 32: # of marked Chinook 40 30 20 10 0 A
Page 33 and 34: CHAPTER 3. RESTORATION SITES Introd
Page 35 and 36: Beer Sheva Park.—At Beer Sheva Pa
Page 37 and 38: Results Seward Park, 2003.—In 200
Page 39 and 40: 4 3.5 Chinook/100 m 3 2.5 2 1.5 1 0
Page 41 and 42: Martha Washington Park, 2003.—In
Page 43 and 44: 120 Chinook/100 m 100 80 60 40 20 s
Page 45 and 46: snorkeling and scuba diving were co
Page 47 and 48: Water column depth (m) . 0.80 0.60
Page 49 and 50: CHAPTER 5. FEEDING AT TRIBUTARY MOU
Page 51 and 52: FIGURE 28.—Location of four south
Page 53 and 54: FIGURE 29.—Photos of sites used t
Page 55 and 56: sampling. At night, Chinook salmon
Page 57 and 58: TABLE 5.—Diet overlap indices (C)
Page 59 and 60: TABLE 7.—Diet overlap indices (C)
Page 61 and 62: TABLE 10.—Diet composition of juv
Page 63: The lack of a large difference betw
Page 67 and 68: shallow to snorkel were surveyed th
Page 69 and 70: Number of Chinook ff 700 600 500 40
Page 71 and 72: column depth used by Chinook salmon
Page 73 and 74: Chinook / m . 5 4 3 2 1 2003 - upst
Page 75 and 76: TABLE 13.—Diet overlap index (C)
Page 77 and 78: (P. Castle, WDFW, unpublished data)
Page 79 and 80: FIGURE 41.—Placement of Scotch br
Page 81 and 82: FIGURE 43.—Photo of a group of ju
Page 83 and 84: CHAPTER 8. LAKE QUINAULT SURVEYS In
Page 85 and 86: FIGURE 45.—Photos of large woody
Page 87 and 88: Similar to April surveys, the nears
Page 89 and 90: Chinook / 100m . 500 400 300 200 10
Page 91 and 92: Tabor and Wurtsbaugh (1991) conclud
Page 93 and 94: FIGURE 48.—Location of south Lake
Page 95 and 96: FIGURE 49.—Conducting visual obse
Page 97 and 98: FIGURE 52.—Photo of a group of ju
Page 99 and 100: ACKNOWLEDGMENTS We wish to thank He
Page 101 and 102: workshop, Shoreline, Washington, No
Page 103 and 104: Paron, D.G., and E. Nelson. 2001. S
Page 105 and 106: Werner, E.E., and D.J. Hall. 1988.
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Nearshore Habitat Use by Juvenile Chinook Salmon in Lentic ...

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