Reese et al.: Distribution and estuarine interactions between wild and hatchery Oncorhynchus keta 
445 
2001; Fukuwaka et al., 2007). Early hatchery fry were 
also notably larger than wild fry and larger fry are 
known to be favored in interactions among chum salmon 
fry (Olla et al., 1998). By comparison, the low overlap 
between the stocks in inner Taku Inlet is not surprising, 
given that hatchery chum salmon would have to migrate 
against a salinity-temperature gradient that they are 
adapted to follow seaward (Salo, 1991). The observation 
that apparent growth of wild fry was greatest in the 
outer inlet where hatchery fish were most abundant, 
and the lack of a negative relationship between condition 
of wild fry and hatchery fry abundance, would indicate 
that hatchery fry were not substantially depleting food 
resources available to wild fry and that negative, den- 
sity-dependent interactions were not occurring or were 
not detected in this study. It should be noted, however, 
that apparent growth is potentially a biased measure of 
actual growth because of the continuous influx of small 
wild fry, shorter residence of larger fry, and size selective 
mortality, which have been documented for chum salmon 
Table 2 
Relationships of wild chum salmon (Oncorhynclius keta ) fry weight to environmental factors and to hatchery chum salmon fry 
abundance from beach-seine collections in littoral habitat by inner and outer location in Taku Inlet, Alaska, during the out- 
migration period for wild fry (late April to mid-June), 2004-05, determined with stepwise multiple regressions (Eq. 2) and cor- 
relation analyses. SST = sea surface temperature; NS = not significant. 
Bivariate correlations with wild fry abundance 
Significance of regression parameters 
Inner 
Outer 
Inner 
Outer 
r 
P 
r 
P 
2004 date 
NS 
Positive P<0.01 
-0.105 
0.048 
0.393 
<0.01 
wild abundance 
Positive P= 0.051 
NS 
0.106 
0.046 
0.167 
0.118 
hatchery abundance 
Positive P=0.018 
NS 
0.127 
0.017 
0.005 
0.961 
SST 
NS 
NS 
0.096 
0.071 
0.219 
0.039 
salinity 
NS 
NS 
-0.012 
0.825 
-0.178 
0.095 
2005 date 
Positive P<0.01 
Positive P<0.01 
0.350 
<0.01 
0.642 
<0.01 
wild abundance 
NS 
NS 
-0.129 
0.034 
-0.414 
<0.01 
hatchery abundance 
NS 
Positive P<0.01 
0.005 
0.933 
0.083 
0.130 
SST 
NS 
NS 
0.309 
<0.01 
0.576 
<0.01 
salinity 
NS 
NS 
-0.011 
0.859 
-0.318 
<0.01 
Table 3 
Results of analyses relating wild chum salmon ( Oncorhynclius keta) fry condition factor to environmental factors and to hatchery 
chum salmon fry abundance from beach-seine collections in littoral habitat by 
inner and outer location in 
Taku Inlet, Alaska, 
during the out-migration period for wild fry (late May to mid- June), 2004-05, determined with stepwise 
multiple regressions 
and correlation analyses (Eq. 3) 
SST = sea surface temperature; NS = not significant. 
Bivariate correlations with wild fry abundance 
Significance of regression parameters 
Inner 
Outer 
Inner 
Outer 
r 
P 
r 
P 
2004 date 
NS 
Positive P < 0.01 
0.098 
0.064 
0.465 
<0.01 
wild abundance 
Positive P < 0.01 
Positive P < 0.01 
-0.036 
0.503 
0.481 
<0.01 
hatchery abundance 
NS 
NS 
-0.086 
0.106 
0.108 
0.312 
SST 
Negative P <0.01 
Negative P = 0.015 
-0.162 
0.002 
0.308 
0.003 
salinity 
NS 
NS 
-0.106 
0.045 
-0.164 
0.124 
2005 date 
Positive P<0.01 
NS 
0.044 
0.473 
0.069 
0.212 
wild abundance 
Positive P<0.01 
Negative P= 0.045 
0.254 
<0.01 
-0.088 
0.110 
hatchery abundance 
NS 
Positive P<0.01 
-0.079 
0.198 
0.278 
<0.01 
SST 
NS 
NS 
-0.060 
0.396 
0.162 
0.101 
salinity 
NS 
NS 
0.144 
0.018 
-0.166 
0.234 
