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Fishery Bulletin 108(2) 
a regression equation from all paired ln-weights and 
ln-lengths (rc = 8475; -700 per year) of field-caught ju- 
venile chum salmon collected during June-August for 
the SECM project from 1997 to 2008. We then used 
this regression equation to predict ln(WW) for each 
experimental ln(FL). Finally, we obtained the CRs by 
subtracting the predicted ln(WW) from the observed 
ln(WW) (Jakob et al., 1996; Brodeur et al., 2004). 
To account for potential stock-related differences 
in condition of the experimental chum salmon (of un- 
known stocks), WBEC was determined for additional 
field-caught fish of known stocks. Historically, between 
70% and 90% of fish caught in June originated from 
Macaulay Hatchery (MH), whereas mixed hatchery 
stocks were present during July (Orsi et al., 2004). 
Otoliths were not retained from the fish used in the 
experimental groups; however, stock of origin was de- 
termined from thermal marks present on the otoliths 
of juvenile chum salmon captured in the study area in 
July and these marks indicated that the fish were from 
unmarked stocks (UM, presumably wild) and MH and 
Hidden Falls Hatchery (HF) stocks. Both hatcheries 
mark 100% of chum salmon released. Energy densities 
were determined (as described above) for these three 
stock groups. 
One-way analyses of variance (ANOVA) were used for 
initial statistical analyses to compare WBEC, %MC, 
FL, and WW of fish across sampling intervals for each 
experimental group and for July stock groups. If sig- 
nificant differences were detected, Tukey’s paired com- 
parison tests were performed to identify the interval 
in which they were found. We used graphical analyses 
to compare the WBEC and %MC for each experimen- 
tal group to the norms (one standard deviation about 
the mean) derived from the entire SECM field data 
set (1997-2008) from June and July (n = 1257; WBEC: 
993.4 ±72.3 and %MC: 79.4 ±1.2). The temporal data 
from the experiments were compared to these norms 
to identify the duration of starvation before the ex- 
perimental measures fell outside the long-term range 
of field values. 
Days starved 
Figure t 
Average whole-body energy content (WBEC, cal/g wet weight) and one 
standard error about the mean for juvenile chum salmon ( Oncorhyn - 
chus keta) starved over time in the laboratory after capture in 
the marine waters of Icy Strait and Upper Chatham Strait in the 
northern region of southeastern Alaska, June and July 2003. The 
grey band indicates one standard deviation about the mean for 
all field-caught juvenile chum salmon examined for WBEC during 
the Southeast Coastal Monitoring project, June-July (n = 1257), 
1997-2008. Significant differences (Tukey’s paired comparisons; 
P<0.05) and percent change between sample intervals are shown 
in inset boxes. 
Results 
The numbers of juvenile chum salmon 
obtained for the two starvation trials included 
101 fish for June and 54 fish for July. The 
higher number of juvenile chum salmon 
available in June allowed nine experimental 
time intervals to be tested, spanning 45 days 
(mean of five days per interval, range of 1-16 
days between intervals). The smaller number 
of juvenile chum salmon available in July 
allowed only five experimental time intervals 
to be tested, spanning 20 days (mean of five 
days per interval, range of 1-10 days between 
intervals). Both experimental groups had 
common intervals at about 10 and 20 days. 
Mortality between sampling intervals was 
minimal in both groups: 13 fish died in June 
(70% during the first 10 days of the experi- 
ment) and two died in July (both during the 
first 2 days). 
The energy content of juvenile chum salm- 
on declined over time in both experimental 
groups (Fig. 1). Initial WBEC was significant- 
ly higher in June than in July (1081.2 cal/g 
WW compared to 960.5 cal/g WW; P<0.001). 
For the June sample group, WBEC decreased 
significantly (P<0.001) by 19% between days 
zero and 19 and by 40% between days zero 
and 45; see table insets in figures for signifi- 
cant differences (Tukey’s paired comparisons) 
between intervals. For the July sample group, 
WBEC decreased significantly (P<0.001) by 
11% between days zero and 20. Overall, the 
relative loss of energy content was almost 
twice as great in June as in July at day 20. 
In contrast to WBEC, %MC of juvenile 
chum salmon increased over time in both 
