262 
Fishery Bulletin 117(3) 
Table 2 
Information about the water-quality stations along the salmon migration corridor from Puget Sound to spawning 
streams in Washington, including the period of record considered for this study of adult Chinook salmon ( Onco- 
rhynchus tshawytscha), frequency of measurements, depth, and parameters used. Data sources are the U.S. Army 
Corps of Engineers, Muckleshoot Tribe, and Eng County Department of Natural Resources. Parameters include 
temperature (Temp), dissolved oxygen concentration (DO), salinity (Sal), and rate of flow (Flow). 
Ship canal location 
Year 
Frequency 
Depth (m) 
Parameters 
Latitude 
Longitude 
Marine, West Point 
2000-09 
Monthly 
1-25+ 
Temp, DO, Sal 
47.663 
-122.448 
Shilshole Bay 
2005-06 
Hourly 
0.5,1,4 
Temp, Sal 
47.666 
-122.400 
Large lock 
2005-06 
Hourly 
1, 10 
Temp 
47.665 
-122.396 
Salmon Bay 1 
2005-06 
Hourly 
5.3, 8.3,11, 13 
Temp, Sal 
47.665 
-122.395 
Salmon Bay 2 
2005-06 
Hourly 
2, 5, 7, 9-13 
Temp 
47.665 
-122.392 
Salmon Bay 
2006 
Weekly 
1-15 
Temp, DO, Sal 
47.665 
-122.394 
Ship Canal West 
2005 
Weekly 
1-9 
Temp, DO, Sal 
47.656 
-122.367 
Lake Union North 
2005-06 
Weekly 
1-12 
Temp, DO, Sal 
47.643 
-122.336 
Ship Canal East 
2005-06 
Weekly 
1-8 
Temp, DO 
47.648 
-122.312 
Lake Washington 
2005-06 
Hourly 
2, 6, 8,10, 20 
Temp 
47.643 
-122.271 
Cedar River 
2005-06 
Hourly 
1 
Temp, Flow 
47.482 
-122.203 
Sammamish River 1 
2005-06 
Hourly 
1 
Temp, Flow 
47.703 
-122.143 
Sammamish River 2 
2005-06 
Hourly 
1 
Temp, Flow 
47.662 
-122.124 
Cottage Creek 
2005-06 
Hourly 
1 
Temp, Flow 
47.717 
-122.088 
Issaquah Creek 
2005-06 
Hourly 
1 
Temp 
47.552 
-122.048 
Sammamish River, 6) Lake Sammamish, and 7) spawning 
tributaries, including the Cedar and Sammamish Rivers 
and Issaquah, Cottage, and Kelsey Creeks. 
Telemetry data indicate the residence time (defined by 
the first and last detections) in each migration segment. 
For fish with only archival temperature data, we inferred 
the transitions between segments by comparing that 
fish’s temperature record with those of fish carrying both 
archival and acoustic tags (Table 1, Fig. 3). Residence 
time by migration segment was evaluated through anal¬ 
ysis of variance (ANOVA) with year and tagging week 
as factors, by using the duration of residence and also 
the proportion of the total time spent in a migration seg¬ 
ment. For fish with acoustic tags, the depth recorded on 
the receiver was used to estimate the ambient tempera¬ 
ture based on vertical thermal profiles at that location 
(Table 2). A 2-way ANOVA was used to test for significant 
differences between years and among weekly tagging 
groups for each metric. 
Mean daily temperatures were calculated from archi¬ 
val tag records of temperatures experienced by individ¬ 
ual fish. The accumulated degree days (DD, mean daily 
temperature exposure above 0°C) for each fish were 
calculated by summing the mean daily temperatures 
it experienced during the entire migration or in spe¬ 
cific migratory segments. To assess possible cumulative 
stress, mean daily temperatures that exceeded thresh¬ 
olds of 18.0°C and 20.0°C were also summed for each 
migrant. These 2 thresholds are associated with stress 
response in Pacific salmon (McCullough et ai, 2009; Eba¬ 
son et al., 2011) and with potential changes in behav¬ 
ior for thermoregulation (e.g., Berman and Quinn, 1991; 
Goniea et a!., 2006). 
Resuits 
Movements and residence time 
All but 1 of the 95 acoustic-tagged Chinook salmon were 
detected at least once in the Lake Washington basin, and 
63 PIT-tagged fish were detected in the fish ladder (40 in 
2005 and 23 in 2006). Archival tags were recovered from 
113 salmon, primarily in spawning streams and in the 
hatchery that raises Chinook salmon on Issaquah Creek. 
Data were also collected from 28 fish with both archival 
and acoustic tags (Table 1). The transmitters provided 
over 450,000 detections for up to 61 d. We reduced the 
number for analysis to 62 fish by removing fish that had 
transmitter failure or malfunction that limited the num¬ 
ber of detections, died or had a regurgitated tag, left the 
watershed, or remained in the lower estuary. After enter¬ 
ing the lower estuary following tagging, 51% of acoustic- 
tagged fish moved continuously upstream, 21% returned 
once to Puget Sound, 16% returned twice, and 13% 
returned 3 or more times. To reach the upper estuary, 17% 
of the fish used the fish ladder and 83% used the large 
lock, as indicated by PIT-tag detections. After reaching the 
upper estuary, 62% of the fish continued upstream, 21% 
returned once to the lower estuary, 9% returned twice, and 
8% returned 3 or more times. 
Individual Chinook salmon displayed diverse patterns 
of thermal experience, resulting from time spent in differ¬ 
ent areas along the migration route: cool in the lower estu¬ 
ary, warm in the upper estuary and ship canal, and cool in 
Lake Washington’s deep waters. In addition to variation in 
thermal experience arising from horizontal movement 
patterns, some fish remained below the thermo-halocline, 
