Martinson et al.: Growth and survival of Oncorhynchus nerka 
497 
Climatic-Oceanic (C-O) regimes 
1 922-46 warm 1 947-76 cool 1 977-2000 warm 
Figure 4 
Annual survival as indicated by residuals from a stock-recruitment curve ( Inf R t+r / E t ] = a + f)E t ) 
for sockeye salmon (Oncorhynchus nerka), from Karluk Lake, Alaska, 1924 to 1989. The 
line is the loess regression line. Bars are the annual values. 
from a fish and involved 
a wider area of the body 
of a fish than the more 
localized sampling with 
forceps done after the 
1950s. 
The inverse relation- 
ship between the regime 
pattern and M3 is consis- 
tent with the idea that a 
density-dependent effect 
on growth occurred dur- 
ing the final year at sea. 
For example, mean body 
weights of pink, chum, 
and sockeye salmon 
stocks in commercial fish- 
eries ranging from Wash- 
ington to western Alaska 
were negatively related to 
increased salmon produc- 
tion from the mid-1970s 
to the mid-1990s (Bigler 
et al., 1996; Helle et al., 
2008). Declines in size 
of chum salmon were 
also documented for car- 
casses sampled at Fish 
Creek, Hyder, Alaska, and 
Quilcene National Fish 
Hatchery in Hood Canal, 
Washington (Helle and 
Hoffman, 1995). Authors 
speculated that a greater 
number of fish in the ocean led to increased competition 
for food and in turn decreased the marine growth and 
size at maturity of salmon. 
Influence of regional C-O conditions 
on mean sockeye salmon growth 
Juvenile growth was correlated with atmospheric cir- 
culation during the winter and spring and weakly 
correlated with sea surface temperature and amount 
of coastal precipitation, whereas immature growth was 
correlated with coastal precipitation and weakly cor- 
related with sea surface temperature and atmospheric 
circulation. Results are similar to those from other 
studies. For sockeye salmon that returned to the Kvi- 
chak River in western Alaska, Ml was positively cor- 
related with SST in Bristol Bay and near the Aleutian 
Islands in the eastern Bering Sea (Isakov et al., 2000). 
Similarly, Helle (1979) found a significant relationship 
(r=0.64; P<0.01) between the mean number of circuli 
formed during the first year of marine growth on 
the scales of age-0.3 chum salmon from Olsen Bay in 
Prince William Sound, Alaska, and the mean summer 
and fall SST, but not air temperature, cloud cover, 
PREC, atmospheric pressure, or seawater density, 
in the GOA from 1957 to 1975. For the same Karluk 
sockeye salmon time series, the early juvenile growth, 
as indicated by the distance from between the last 
freshwater and first marine circulus to the end of the 
9 th circulus, was negatively correlated with the num- 
bers of juvenile pink salmon fry (r=— 0.77; P=0.002) 
released from hatcheries in Prince William Sound, 
Cook Inlet, and Kodiak, and the distance from the 9 th 
circulus to the end of the first marine annulus within 
Ml was positively correlated with summer SST in the 
GOA (r=0.49; P<0.01) (Martinson, 2004). A stronger 
density-dependent effect on early marine growth indi- 
cates a masked influence of C-O conditions on growth 
(Martinson et al., 2008). 
Interrelationships among regional C-O conditions, 
mean growth, and annual survival of sockeye salmon 
The higher survival during the warm regimes and lower 
survival during the cool regime indicate that marine 
climate influenced the production of sockeye salmon 
from Karluk Lake. Results are consistent with other 
studies showing a strong relationship between various 
C-O indices and salmon survival. Regional scale covaria- 
tion in survival rates of pink, chum, and sockeye salmon 
were more closely related to coastal SST during the 
first summer at sea than surface salinity or upwelling 
