203 
NOAA 
National Marine 
Fisheries Service 
Abstract— Seasonal and annual ma- 
rine growth of chum salmon ( On - 
corhynchus keta ) from Fish Creek, 
Alaska, during 1972-2004 and from 
Quilcene River, Washington, during 
1973-2004 were examined in rela- 
tion to abundances of chum salmon 
and pink salmon ( O . gorbuscha) and 
climate indices from that period. 
Pink salmon abundance indices were 
included in the analysis because of 
evidence for density-dependent ef- 
fects on chum salmon growth and 
survival. In linear regression mod- 
els, growth was negatively related 
to abundance of chum salmon or to 
the combined abundance of pink and 
chum salmon during the middle ju- 
venile (July-Sept), 1 st immature, 2 nd 
immature, and maturing stages for 
the Fish Creek chum salmon and 
the 1 st immature, 2 nd immature, and 
maturing stages for Quilcene River 
chum salmon, indicating possible 
density-dependent effects on growth. 
Mid-juvenile and maturing growth 
models for the Fish Creek chum 
salmon and the maturing growth 
model for Quilcene River chum 
salmon performed well in model 
validation, when model predictions 
were tested against 20% of the data 
that were not used for model specifi- 
cation, and provided insight into the 
effects of climate and abundance on 
growth of chum salmon from 1972 to 
2004. 
Manuscript submitted 30 June 2015. 
Manuscript accepted 5 February 2016. 
Fish. Bull. 114:203-219 (2016). 
Online publication date: 3 March 2016. 
doi: 10. 7755/FB. 114.2.7 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Fishery Bulletin 
ftr established 1881 -<?. 
Spencer F. Baird 
First U S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Effect of population abundance and climate 
on the growth of 2 populations of chum 
salmon lOncorhynchus keta ) in the eastern 
North Pacific Ocean 
Ellen M. Yasumiishi (contact author ) 12 * 
Keith R. Criddle 1 
John H Helle 1 3 
Nicola Hillgruber 1 ' 4 
Franz J. Mueter 1 
Email address for contact author: ellen.yasumiishi@noaa.gov 
1 University of Alaska Fairbanks 
School of Fisheries and Ocean Sciences 
17101 Point Lena Loop Road 
Juneau, Alaska 99801 
2 Auke Bay Laboratories 
Alaska Fisheries Science Center 
National Marine Fisheries Service, NOAA 
Ted Stevens Marine Research Institute 
17109 Point Lena Loop Road 
Juneau, Alaska 99801-8626 
3 2427 O'Day Drive 
Juneau, Alaska 99801 
4 Thunen-lnstitute of Fisheries Ecology 
Wulfsdorfer Weg 204 
22926 Ahrensburg, Germany 
Over the last century, the quan- 
tity of chum salmon ( Oncorhynchus 
keta ) and pink salmon (O. gorbus- 
cha) available for harvest in North 
America has fluctuated on a multi- 
decadal scale with harvest peaks in 
the 1930s and the 1990s and lows 
in the 1950s, 1960s, and 1970s (Eg- 
gers et al. 1 ; Ruggerone et al. 2010). 
From the midl970s to the mid-1990s, 
increases in salmon production were 
attributed to a combination of causes: 
namely of hatchery supplementation 
(Eggers, 2009), increased survival of 
wild stocks due to favorable ocean 
conditions (Beamish and Bouillon, 
1993; Francis and Hare 1994; Hare 
and Francis, 1995; Hilborn and Eg- 
gers, 2000; Morita et ah, 2006), and 
improved management of wild stocks 
(Wertheimer, 1997). 
Concurrent with increases in 
1 Eggers, D. M., J. R. Irvine, M. Fukuwa- 
ka, and V. I. Karpenko. 2005. Catch 
trends and status of North Pacific salm- 
on. NPAFC Doc. 723, Rev. 3, 35p. 
salmon production from the mid- 
1970s to the mid-1980s and 1990s, 
reductions in the average body size 
were observed in Pacific salmon from 
North America and Asia (Bigler et 
al., 1996; Helle and Hoffman, 1998; 
Bugaev et ah, 2001), indicating pos- 
sible density-dependent effects on 
growth in the ocean. Based on these 
correlations, a hypothesis was for- 
mulated that there might be a finite 
carrying capacity for Pacific salmon 
in the North Pacific Ocean, limited 
by the amount of food available to 
support fish growth (Helle and Hoff- 
man, 1998). 
Density-dependent influences on 
growth have been well documented 
for salmon in the Pacific Ocean. Ju- 
venile pink and chum salmon have 
a high degree of overlap in diet off 
southeast Alaska and within Prince 
William Sound in the Gulf of Alaska 
(GOA) (Auburn and Ignell, 2000). The 
marine survival of chum salmon and 
stomach fullness of juvenile chum 
