Fergusson et al.: Effects of starvation on energy density of Oncorhynchus keta 
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Table 1 
Average fork length (FL, mm), wet weight (WW, g), percent moisture content (%MC, [(1 -dry weight/WW)x 100]), and whole 
body energy content (WBEC, cal/g WW), for unmarked (presumably wild) and hatchery stock groups of juvenile chum salmon 
( Oncorhynchus keta ) captured in the marine waters of Icy Strait and Upper Chatham Strait in the northern region of southeast- 
ern Alaska, July 2003. Standard errors are given in parentheses. 
Stock group 
n 
FL 
WW 
%MC 
WBEC 
Unmarked 
13 
120 (1.7) 
17.5 (0.8) 
80.4 (0.1) 
954.0(5.7) 
Macaulay Hatchery 
10 
137 (3.0) 
29.0(1.5) 
80.3 (0.2) 
957.5 (14.3) 
Hidden Falls Hatchery 
10 
127 (2.9) 
22.1 (1.6) 
80.4 (0.1) 
959.5 (9.6) 
experimental groups (Fig. 2). Initial %MC was 
significantly lower (P<0.001) in June than in 
July (77.8% compared to 80.1%). For the June 
sample group, %MC increased significantly 
(P<0.001) by 4% between days zero and 19 and 
by 9% between days zero and 45. For the July 
sample group, %MC increased significantly 
(P<0.001) by 1% between days zero and 20. 
Overall, the increase in %MC was four times 
as great in June as in July at day 20. 
Changes in the WW and FL of juvenile chum 
salmon over time were not consistent between 
the experimental groups (Fig. 3). For WW, 
initial values did not differ (P>0.05) between 
June and July (14.2 compared to 13.6 g). For 
the June sample group, WW decreased signifi- 
cantly (PcO.Ol) by 39% between days zero and 
45. For the July sample group, no significant 
(P>0.05) differences in WW were observed. 
Similarly, initial FL values did not differ 
(P>0.05) between June and July (112 com- 
pared to 110 mm). For the June sample group, 
FL did not change significantly (P>0.05) be- 
tween days zero and 45. For the July sample 
group, FL increased significantly (PcO.001) by 
19% between days zero and 20. 
The CR of juvenile chum salmon became 
increasingly negative over time in both ex- 
perimental groups (Fig. 4). Initial CRs were 
positive in both months, but June CRs were 
lower than those for July. For the June sample 
group, CR declined significantly (P<0.001) be- 
tween days zero and 19 and between days 
zero and 45. For the July sample group, CR 
declined significantly (P<0.001) between days 
zero and 20. Mean CRs shifted from positive 
to negative after approximately 10 days of 
Days starved 
Figure 2 
Average percent moisture content (%MC, [(1-dry weight / wet 
weight) x 100]) and one standard error about the mean for juve- 
nile chum salmon ( Oncorhynchus 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 stan- 
dard deviation about the mean for all field-caught juvenile chum 
salmon examined for %MC 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. 
starvation in each sample group and continued to de- 
cline, indicating increasingly poor condition for a given 
size fish. 
Hatchery stock group did not affect the WBEC or 
%MC of the July-caught juvenile chum salmon. A total 
of 33 fish were examined: UM (n- 13), MH (n=10), and 
HF (n = 10) (Table 1). Stock had no effect on WBEC or 
%MC (P>0.05). However, WW and FL did differ signifi- 
cantly (P<0.001) among stocks and were highest for the 
MH stock and lowest for the UM stock (Table 1). 
Discussion 
To our knowledge, this is the first published study of 
the change in energy density and %MC of field-captured 
